grow light bulb

Air Cooled Lighting

As temperatures increase in the summertime, the heat produced by lighting systems becomes more of a problem. Air-cooling these systems can become necessary.

How do Air Cooled Lighting Systems Work?

Air cooled reflectors use a glass bottom to create and airtight tunnel. Cool air is blasted through it, past the face of the lamps, taking away the excess hot air with it and cooling the lamp surface. The plants below still get the benefit of the light, but without suffering the effects of excess heat.

Be sure to keep the glass surface clean, however, as this is where beneficial light might be blocked or reflected by dust or moisture build-up on the glass surface.

Benefits of Air Cooled Lighting Systems

Removing heat with an air-cooled system prevents heat build-up in the summer, especially among the plants closest to the light sources. Lights can also be places closer to plants without burning them – this can become a factor especially as the summer season lengthens and plants grow higher, closer to ceiling-mounted lights. Small grow rooms, like those made in closet spaces, are especially susceptible to overheating, and a cooling system can save your plants from total destruction. It also reduces the strain on your ventilation system and can help to increase CO2 levels without having to add any through artificial means.

Common Misconceptions

There are a lot of myths around air-cooled light systems, so let’s address them directly.

Bulb Heat Is Lost

This is not quite accurate. HID lamps produce two types of heat when they are on. The first is convection heat. Air moving over the surface of the light can greatly reduce this form of heat by moving it away, down the duct, as it conveys the heat. In effect, it releases the heat at a destination outside of the grow room, where it otherwise would have been conveyed into it.

The second is radiated heat. Radiated heat moves in waves through the glass and into the room. Moving air past it does not significantly reduce radiated heat.

Air Cooled Reflectors Are Better Because They’re Closer

This is true in most cases – but keep in mind that the closer the reflector is to the tops of your plants, the more focussed the light is. If you want to cover a wider area, lifting the light may be of greater overall benefit than dropping it close. Aim for the optimal light levels at the plant surface: 800-950 micromoles/s.

Light Is Lost Through Glass Panel

High-quality, flat glass that is well-suited to this purpose will drop light efficiency by as much as 4-5%. This is less a factor than the loss of light produced when lamps are raised up higher to prevent overheating. Of the two options, the cooling system actually results in more light reaching the plants. Keeping the panes clean and the reflector closer to the plants will give best results.

Colder Air Blown Through Is Better

This is accurate, but the gases in the lamp’s arc tube need to be at the appropriate temperature to produce the optimal amount of light too, so overdoing it will create losses along with any intended benefits, and they will cancel each other out. The purpose of an air-cooled light is to remove excess heat, not to decrease as much heat as possible. It is about balance. A good rule of thumb is to use cooling air of a similar temperature to that in the grow room itself. This will also prevent the build-up of condensation or fogging on the glass, allowing for all of the available light to continue passing through the glass from the lamp and onto the plants below.

Want to Buy Grow Lights or Hydroponic Fans?

Here at Acorn Horticulture, you can buy a range of hydroponics online with home delivery or collection.

Shop Grow Lights here.

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grow tent setup

Grow Room Ventilation Guide

Article sections: Benefits | How To | Faq’s

One of the key benefits of indoor growing is that the season goes on and on and on – but there are some drawbacks too, if you’re not careful. A few simple tips and tricks will help to eliminate these though, and help you maximise the advantages.

Among the most important things to consider is airflow – achieved through proper ventilation. This is more than just popping a fan in a corner; your ventilation system should be tailored to your particular grow room, and should function according to the differing needs throughout the year. This may sound daunting, but it really isn’t that difficult.

Below we’re going to go through the reasons you need proper ventilation, how to set up the right system for your situation, and some tips on buying the right things without breaking the bank.

Benifits of Grow Room Ventilation

There are several reasons why grow rooms need good ventilation. Outside, plants are in the midst of natural breezes, sunshine, changes in temperature, natural evaporation, and precipitation – rain and/or snow. Some of these conditions can be a strain on the plant, and indoor growing removes that strain. Some of these conditions also help the plant though, and proper ventilation (along with appropriate lighting and space) will provide these vital elements to your grow room.

Ventilation comes in two main parts: the intake, and the extraction. Both are important to your indoor grow room conditions, and each of them needs to work in balance with the other.

So what will the right system do?

Control Heat

As well as the ambient temperatures in your house, the grow lights you use will also add a lot of heat. A few degrees might not feel very different to a human being, but to a plant it can mean a huge difference in moisture loss, crop volume, and overall health. The ventilation system removes excess heat.

Control Wind

A little breeze can toughen up plants, but it can also stress them in the process. A grow room situation removes the heavy winds, but it also removes the lighter ones that can cause a plant to toughen up stems – and tougher stems can bear more fruit without breaking.

Humidity

Some humidity is good for plants of course, though the amount varies from species to species. Plants emit water of their own, too, as part of a healthy circuit of water up from the nutrient-rich roots to the shoots and leaves. But this humidity can build up around them in an enclosed space. Too much of it and plant diseases can develop, pests can move in on weakened plants, and mould and mildew can become a real problem. The right ventilation system will remove enough of this humidity to prevent these issues, but not so much that it endangers the health of your plants.

C02 Management

Plants need CO2 like human beings need oxygen. They absorb it through the daylight hours and it helps to fuel their nutrient cycle. A sealed grow room (or tent) can mean a steady depletion of CO2 and subsequent slowing of growth and productivity – basically it starves the plant of needed nutrition. Bringing in fresh air replenished the CO2 levels and allows the plant to continue its regular cycle – producing better growth and yields.

Pests/Diseases

Many pests do well in stagnant, humid conditions. Such places are favourite spots for the laying of eggs and the growth of mould and mildew. A dry topsoil layer discourages the laying of eggs and turns off pests like spider mites and fungus gnats. Even if such pests are present, controlled conditions can slow the growth cycle and give plants more of a fighting chance against them. A balanced ventilation system is a good defensive measure against these issues.

Buying a Ventilation System

If you are going to go to the cost of setting up a grow room (or tent), it doesn’t make sense to stop short of the line and spend your money on a system that starves your plants, reduces yields, or encourages pest infestations. Finish strong with the right ventilation system and the value of the money you spend will increase – as will your enjoyment when you bring in those big, satisfying yields.

You can buy everything you need to control your grow room environment on our website here.

How to Ventilate Your Grow Room

There are two types of fans you’ll need – think of them as the two halves of a full system, that need to be in balance for the whole system to work.

1. Oscillating Fans

Oscillating fans are not expensive, and give great value for the money spent on them. The constantly move air around the room, keeping all areas in and around each plant’s growing space well-ventilated.

They can easily be moved from one location to another, so most people experiment a little with where they are most effective in a particular grow room configuration, or with particular plant species and placement. It isn’t too complex though – simply make sure that the air flow reaches all areas of the room. This is often best achieved by using more than one fan, especially in larger rooms or among denser plant types.

A word of caution though: Don’t aim the fans directly at your plants. This can cause ‘wind burn,’ an unhealthy drying out of the plant tissue, causing damage and stress to the afflicted plant.

Once you have decided on your oscillating fan needs, it is time to turn attention to the extractor fan part of the system.

2. Air Extractor Fans

Extractor fans pull old air out of the growing room, which creates vacuum pressure which pulls in fresh air. This fresh air, as mentioned above, is vital for supplying your plants with enough CO2 for their nutritional system needs.

The goal is to replace the air in the grow room or tent, once every minute or so.

That means that it is relatively easy to figure out what size fan you need for a certain size of room. Take the volume moved by the fan (this will be listed in the product information for the fan – we’ll get into it in a bit more detail below) and compare it to the volume of the grow room. The fan should move roughly the same amount of air in a minute that the room can hold. As long as it is moving that amount of air, and the oscillating fans are circulating the air within the room, you can be confident that you are providing your plants with what they need to thrive.

A little tip for new growers: Set up your fans and light systems before adding any plants to the room – that way you won’t have to work around them or risk damaging them.

NOTE: Understanding Fan Strength

Fans are given a rating based on how many cubic feet of air they move in a minute. This is the CFM rating (Cubic Feet per Minute).

Before you can choose the right CFM level, you’ll need to know the volume of your grow room or tent, and the exhaust efficiency.

Measure the length, width and height of your grow room. Multiply them together (L x W x H). If your room is an irregular shape, then figure out the volume of each portion of it separately, then add them together. Many grow tents have the volume listed in the product information.

Note this number – you’ll need it later.

Next you’ll need to determine the efficiency drop. This is the loss of fan efficiency due to the resistance of filters, and in some cases, the volume of the room. The length of duct between the fan and the filter is also a factor. Don’t panic! Here is a good rule of thumb (well, two rules of thumb!): The first is, take the volume of the room and multiply it by 125%. Use this as your room volume. The second is that, if you have a long duct path, multiply it by three; a short duct path, and only multiply it by two.

So, it looks like this:

(Volume of room x 125%) x (2 or 3, depending on duct length) = needed CFM

Let’s plug in some easy numbers as an example. Say your grow room volume is 100 cubic feet, and your duct length between the fan and the filter is short. Multiply the grow room volume by 125%, then by 2, and you have your needed CFM. In this case, that’s 125 x 2 = 250.

So for that example, you’d need a fan with a CFM of at least 250 (but not a huge amount higher, or you risk over-drying the room).

Intake Types (Passive vs Active)

As mentioned above, pulling air out of the grow room will suck fresh air into it (this is known as passive intake), but sometimes more help is needed to ensure a steady, easy flow – in these cases you might want to consider a, active intake system, one in which air is also pushed into the room by an intake fan.

A passive intake system needs an intake hole at least three or four times larger than the exhaust hole. This aids in easy flow and helps to prevent over-working your fan. Using more than one intake hole can also make up this total, and can help even out the fresh air when ventilating rooms of irregular shape.

An active intake system blows air in with a fan. This reduces the workload on the extractor fan(s) and you’ll be fine with an intake hole the same size as the exhaust hole.

Humidity

Plants need humidity for proper growth, but too much of it can cause disease, aid in pest infestation, and can hamper growth and yield volumes and quality. Part of a healthy indoor grow room requires constant monitoring of humidity levels.

The leaves of plants will give off their own humidity through a process known as transpiration. This loss of moisture from the ends of the branches of a plant causes suction from the roots and lower portions of the structure, drawing up new moisture that is rich in nutrients to replenish the plant.

If a plant dries out, this process stalls and growth ceases – sometimes to a fatal degree. If ambient humidity is too high, evaporation ceases and the process is stalled from the top end, causing similar end results.

Adjusting humidity is, however, quite simple. To lower it, vent humid air out of the room and take in dryer air through the intake vents. If the outside air is also very humid in your area, you may require a dehumidifier to do the job. To raise humidity, slow the exhaust system temporarily to allow the humidity given off by transpiration to build up a little. You may even want to seal up the grow room for a temporary period to allow humidity to increase.

Monitor each situation closely, as humidity can change quite quickly, and you won’t want to over-adjust in either direction.

Some species of plants, and larger plants in general, need more humidity, so you may need to adjust the grow room conditions as your plants move through their growth cycles.

CO2 (It’s a fine balance)

In some cases, you may want to increase CO2 levels in your grow room by injecting more CO2 artificially. This is similar to giving a human being oxygen when the person is injured or needs to recover from a period of high exertion.  In a grow room situation, however, there are some factors to consider.

First of all, the level of CO2 necessary to benefit plants is dangerous for human beings. CO2 leaking from the augmented grow room could cause health problems in your home.

Secondly, your grow room will need to be sealed. CO2 injection needs very high levels to be effective, and that concentration will not be reached in a ventilated grow room, even if the fans are turned off. In addition to this, you’ll want bright grow lights to enable your plants to take full advantage of the added CO2.

In most cases, CO2 injection is not necessary for an otherwise optimised grow room setup.

FAQ’s

Below are some frequently asked questions around grow rooms and grow room ventilation:

How large should my fan be?

You will need to calculate the CFM of your room using the formula we explained in the article above. This is not difficult to do, and can mean the difference between strong success, or total failure. A few inexpensive oscillating fans will also make your ventilation system more effective.

Does my bulb size matter compared to the fan?

You should get at least a 6-inch diameter fan, as this is the usual diameter of the light hood’s opening. It is a good idea to measure first, as they are also available in 4-inch and 8-inch sizes.

How do I know which type of fan to choose?

There is a wide variety of fans out there. Look for an in-line duct fan with a CFM higher than your calculated need for your grow room (see above article). Choose a make and model that fits with your budget and has good reviews. Check whether the fan comes with a filter included, or if it is an additional purchase and factor that into the cost.

What is Negative Pressure?

When the exhaust (out take) fan pulls air from the room, it creates a vacuum within the room. That vacuum is negative pressure. Air from outside the room rushes in to even out the pressure.

What’s the best type of ducting?

For most systems, the best choice is flexible aluminium. It is not expensive and is by far the easiest to install. Other options include heavy duty rectangular ducting or insulated ducting. The key factor is size – the smaller the duct size, the greater the air resistance. Bigger ducts are better for longer distances and to reduce the workload on fans.

Can I make my ducting more efficient?

There are a few things that can improve the performance of your flexible aluminium ducting. The first is to smooth out the curves and corners as much as possible, and then to smooth out the wrinkles in the tube itself. The shorter the length, and the fewer the curves, the lower the resistance.

What size intake fan do I need?

If you are using a passive intake system, you don’t need an intake fan. If you want an active intake system however, you should choose a fan that is the same size as your out take (exhaust) fan.

You can shop a range of Hydroponic supplies here online at Acorn Horticulture, including a fantastic range of propagation and grow tents.

coco coir

Coco-Coir Grow Guide – Top Tips and Nutrients for Growing in Coco

Here we go over some of the essential info you need to grow plants in Coco-coir.

What Is Coco Coir And How Is It Made?

Coco coir is a by-product of coconut fibre. It has been used for centuries in the West, though popularity temporarily waned as good-quality coco was in short supply and what was available degraded too quickly to be viable or cost-effective in most growing situations.

With the more recent growth in the popularity of organic gardening, and the availability of high-quality coco, it has seen a resurgence as an environmentally sustainable substrate.

Coco coir is made of coconut shell fibre. Coir is extracted from the shell and ground into a growing substrate. The coconut is cured and mechanically treated, in a process called ‘retting,’ which takes a little over a week to complete – compared to the six months it took centuries ago. This makes it much more cost effective too.

The coconut fibre is combed off of the shells. This fibre is called coir. It is dried, pressed into a shape (such as a brick, disc, or pot) or left as a loose much which can be bagged. At this stage, it is ready to be used.

Types Of Coco Coir

Variations in this process can produce three types of coco coir: pith, fibre, and chips. Some people use only one kind, while others use more than one in combination.

Coco pith, sometimes called peat, is a rich brown moss-like material. It is excellent at absorbing and holding water, which has its benefits of course, but if used on its own it can overwhelm a plant with moisture and provide the conditions for rot to set in.

Coco fibre is a stringier material, usually sold in bundles, which allows more airflow and so you get an increase of oxygen to the root systems of your plants. The fibres don’t hold as much moisture as the pith ones do, but it can be reused a few times while it breaks down, and is excellent for use mixed in with the pith.

Coco chips are made up of chunks of coir. The chunks are porous, so they do retain water, but they hold up very well too. Of the three, this is the best choice if you are going to use only one, rather than a combination.

The best method, once you gain some experience using these different products, is to mix your own combinations of these three, to customise your growing supplement to the conditions you desire. Until you get to that point – or if you simply want to save yourself the added time and effort – there are commercially-prepared mixtures available for sale. You can buy dried bricks, for example, and all you need to do is add water. As with most commercially available products though, quality tends to be sacrificed in order to minimise production costs. If you truly want the best, you should learn to mix it yourself.

Pros and Cons of Growing in Coco

Pros

There are pros and cons of using coconut coir as a growing medium.

One benefit is that you will get quicker harvests and bigger yields. If you use coco coir for drain-to-waste growing, your plants will not need to search for nutrients as much, and that saved energy will instead go into growth and production of the crop itself.

Another benefit is that the coco coir can retain water well, without clogging up the soil or making it too dense. The airflow and looser soil can help plants to develop good root systems with good air exposure, without drying them out.

The pH value of coco coir is neutral (5.2-6.8) – at least to begin with – so you won’t need to worry about it skewing the pH of your soil one way or another. It will fluctuate over time, however, so you’ll still want to keep an eye on things.

Coco coir can minimise harmful pathogens and even reduce the risk of infestation by pests. Coco coir has antifungal properties, helping to keep roots happy and healthy, too.

Most gardeners are aware of environmental issues and have a desire to garden in earth-friendly ways. Coco coir is great for that. A coconut tree produces 150 coconuts, on average, and much of the fruit – the shell – would normally go to waste. Coco coir is made from this by-product though, so it not only helps your garden, it is beneficial to the earth as well.

Coco coir can be reused – if it’s treated properly. When correctly prepped, coir is durable and holds up well for more than one harvest, making it even more economical and environmentally friendly… not to mention giving you a great crop!

Cons

Yes, there are a few cons to using coco coir too. These are minor though, and any potential ill effects can be lessened with a little care.

Salt Content – depending on where you get your coco coir, and how it is produced there, there can be a high salt content. Some manufacturers rinse their coco coir before packaging, but others don’t. If you buy the cheapest available, you’ll probably need to rinse it yourself to ensure you don’t raise the salt content of your soil to a dangerous level.

Coir bales are sometimes treated with chemicals to prevent pathogens from blooming inside of them. The chemical residue can affect certain crops and hamper plant growth. A visit to the manufacturer’s website or a good read of the package small print can let you know if there were chemicals used on the product.

Coco coir has a high cation exchange rate, so it stores and releases nutrients very freely, as needed. It does, however, tend to lock up calcium, magnesium and iron. You’ll want to boost these using a supplement to ensure the best results for your plants and crop yield.

How to Grow in Coco-Coir – Step by Step

1. Pre-Soak Coco

In order to make sure your plants get the necessary amount of nutrient salts, you should pre-soak your coco media before planting. To do this, simply apply a ¾ feed to full strength feed until you see a run-off begin to collect in the tray under the container.

2. Controlling the PH and CF

Keep an eye on the pH and EC/CF of your nutrient solution. This will ensure that you get the most from your plants by keeping them as healthy and stress-free as possible.

PH Control

Your pH level will tell you the acidity levels of your soil. It should be 6, as an ideal, but anywhere between 5.5 and 6.5 will be a comfortable range for most plants and will ensure that most nutrients are available when your plant needs them.

To adjust the PH, Add nutrients and boosters (before altering the pH), then alter the levels with pH Up or Down (a single drop at a time), then if you add too much one way or the other, adding water to help neutralise it.

CF/EC Control

The CF/EC indicates how strong your feed is. The ideal CF depends on your growing cycle and how hard your water is. For young plants, your CF should be 6-12. As plants are getting established, it should be a bit higher, around 10-16. Once the plant is mature, 15-20 is best.

To adjust it, add water to reduce the CF, and simply add more concentrate to increase the CF.

3. Adding Moisture

The best balance for healthy root growth, is for the growing medium to be both airy and moist. This promotes drainage – which prevents rot setting in – but still gives the roots access to what they need to grow and provide nutrients and moisture to the rest of the plant.

To check the moisture, squeeze the media. If water runs out, it is too wet. If no moisture appears at all, it is time to water it. As you become an expert in the media and your various pots, lifting them up can tell you if they are heavy enough (adequate water) or too light (getting dry).

4. Proper Irrigation

Run off is the term for the excess feed that pools in the dish under your pots when you water. You should see 20-30% of your watering coming through as run off each day. This will ensure the right nutrient concentration. If water does not flow freely through the media, it may be waterlogged and need care to increase air flow and drainage.

How to Remove Run Off

Do not let the plants sit in the run off. It should be removed before the plant can reabsorb it.

Mature plants should be irrigated 3-8 times per day, for 2 to 5 minutes. Alternately, you can measure by applying 4-6 litres per metre square. This can also vary with plant size and the temperature of the surrounding air.

No Run Off? Read this…

If you don’t get run off, but you know your soil is of a suitable density and drainage, then you can prevent nutrient build-up by reducing the strength and frequency of the feed. Try ¼ strength, every third feed in winter and every second feed in summer (when it’s warmer and there is more growth).


Wow, it looks like you’re all set to grow with coco!

If you need any other hydroponics equipment or materials, then consider browsing our range online here.

We stock everything from grow lights, to grow tents, and propagation.

You can also shop our nutrients and boosters here.

grow tent setup

Grow Tent Setup – How to Set up a Full Grow Room

Whether you’re getting started with your first grow room, or you just want a refresher on the best method, keep reading for our step by step guide.

1. Make Space

There are several factors to consider when designing your own indoor grow room. Here are some to think about.

Match Your Growing Goals

Even quite a small space is suitable for a grow room, but it depends on what you want to grow, and how much of it. You can convert a room or closet, or you can use a grow tent.

Power Outlets

A couple or regular light sockets will often suffice for a one or two light grow room setup. If you need more, you could use an extension lead, or consider some custom wiring work.

Water Source

Never use unfiltered rain water, as it may contain toxins and other impurities that are harmful for your plants. Filtered water is best.

Noise Pollution

If you use certain lights, fans or pumps, these can produce noise that may disturb you in other parts of your home, so be sure to place a grow room in a location that is most suitable to the degree of noise it is likely to produce.

Solid Flooring

Carpets hold moisture and insects, and can lead to mould and infestations, so it is best to use a clean, wipeable flooring like linoleum.

2. Light Control

Reflective sheeting is a great way to keep light in your grow room, making the most of your lighting efforts and power. It is important to keep external light out, as well, if you are controlling your light cycle and do not want regular daytime light to interfere with it.

3. Mapping Out Your Grow Room

Whether you are using the whole room, part of a room (as with a grow tent) or a converted cupboard, you will want to plan out where everything will go, ensuring room to move around within it to care for and harvest from your plants. You also want to make sure your grow lights are not too powerful for your plants, but still provide ample light for good growing.

You have a few options of how to setup your grow room:

Use The Whole Room

One grow light is not enough for a large room. Provide a minimum of one light for every 1.2m2. Some people divide a large room into several tents for greater control.

Grow Tent/Room in a Room

Using a grow tent is the cheapest way to set up a grow room. These are designed to prevent infestations and diseases, to keep light in (or out), and are great for consistency of climate within the tent. They can also protect the rest of your house from potential damage from humidity.

Convert Small, Enclosed Room/Space

Small spaces, like closets, may seem easier to set up, but they do have some problems associated with the small space.

For one, they heat up more easily. A higher space, at least 1.4m, is a good way to help control this as it gives the heat somewhere to rise to. Keep your bulbs within the 250-315-watt range. Finally, make sure there is good airflow through the use of an extractor fan and air intake holes (an air input fan, with outflow holes, works even better).

4. Lighting System

Use at least one grow light in your grow room, and add others as size demands. Remember not to over-light you grow room, as this can cause damage and other problems to your plants as well.

What is a Grow Light?

Typical grow light systems are made up of a ballast (which controls the energy supply to the light), the lamp (the light source itself), and the reflector (which aims or intensifies the light).

Main Light – MH, HPS, LED

Metal halide (MH) lamps have been losing popularity in favour of dual spectrum HPS (High Pressure Sodium) lights, which do not require a separate sodium light when it comes time for flowering. Metal halide does produce more blue light, which helps for more vegetative growth, but lacks the sodium component for flowering.

Many people also use LED lights throughout the process, and fluorescent lights from propagation.

Extra Lights – Plasma, CDM

Supplemental grow lights can broaden the spectrum outside of the PAR range, which does not increase growth, but can increase the quality of the yield. Of these, Plasma has more wavelengths outside of the PAR range, whereas CDM have many outside the PAR range, but also more within the PAR range than plasma lights do. A CDM can sometimes be used as a main grow light, if proper reflectors and bulbs are used.

Supplemental bulbs are just what the name implies – supplemental. You will not require one, but the use of one or more of these may increase both plant growth and yield.

Consider the Costs

Choose lights with economy in mind. Some take a lot of power and are not suitable for many home purposes. Compare the input with the output, and then consider the area you are planning to light with it.

Money Saving Tip – Running at Night for Cheaper Power

Remember that you are controlling the ‘daytime’ and ‘night-time’ cycles for your plants, and you can put them whenever you want to. Power is generally cheaper at night, so keeping your grow lights on during the night and off during the day can be a great way to lower costs. The lights also produce some heat, so keeping them on during the cooler parts of the 24-hour cycle can save on heating the grow room and keep a more constant climate within the room or tent.

If you need to go into the grow room during daylight hours, when your plants are in their night cycle, try using a headlamp, so as not to disturb them.

4. Fans, Filters & Air Control

An air exchange system is a great way to control the climate in a grow room, especially for beginners. Plants consume CO2 and give off moisture. Bringing in fresh air will flush out that CO2 and moisture – and can even dissipate some of the heat from your lamps.

The size and power of air exchange system you’ll need will depend on the intensity and number of your lights, the size of the grow space, and the time of year (summer, for example, will require more air flow than winter).

Extractor Fans

To determine how many extractor fans you will need in your setup, find the volume of the grow room by multiplying length times width times height. Multiply the result by 60, and you will have the amount of air you need to extract each hour.

Certain conditions may add a modification to that number, here are some estimates:

  • a warm attic will need 20% more
  • a cool basement needs 15% less
  • south-facing rooms need 20% more
  • a carbon filter adds 20% to your needs
  • long ducting needs 20% more
  • air cooled lighting means 25 – 30% less extraction needed

Fan speed controllers are a good idea too, as they will slow down or speed up your fan according to current conditions.

Intake Fans

For smaller rooms, using vents to bring air in is sufficient. For larger ones, or for rooms with more intense lighting, you will want to use air intake fans. Intake fans should be slightly less powerful than the extractor fans they work with – about 15% to 20% is suitable.

Where possible, placing the extractor fan(s) on the opposite side of the room from the intake fan(s) is ideal. Placing them too close together can result in a strong current of air between the two fans, and a lack of air current throughout the rest of the room, making them far less effective.

Safety Advice

Grow room lighting systems tend to be very safe. They use low wattage and when wired correctly are like any other appliance or light bulbs. Since they are used in a growing situation, however, there are some common-sense measures that should be taken to ensure they don’t become dangerous.

Keep wiring up and out of the way. This prevents damage to connections and keeps the electrical power out of the water if there is a flood or leak in another part of the grow room system.

Ballasts and other components should never come into contact with water, unless specifically designed to do so. Small children and animals can sometimes cause damage to systems, or the placement of systems, and appropriate measures should be taken to keep the grow room off-limits where appropriate. Uncoil extensions and reflector cables to prevent overheating.


Now you’re ready to setup your grow room!

If you need any more products, we have a great range to buy online here at Acorn Horticulture.

We also have discreet click and collect services, with our shop based in Sheffield just off the M1, for easy reach within a lot of the UK. You can get directions on Google maps here.

spider mites on leaf

Spider Mites – How to Kill and Prevent Spider Mites on Plants

Quick links: What are they? | Identify | Natural Solutions | Chemical Solutions | Prevention | FAQ’s

It could happen to you your plant starts to look a bit odd, fading from bright green to sickly yellow in just a few days. Upon a closer look, it’s clear what is going on – Spider mites!

Subtle, potentially deadly to the plant, and much more common than one would think, these little parasites can sneak their way into your home and infest your favourite plants – and they must be taken care of to keep your indoor garden looking its best. If they aren’t controlled or eliminated, they can spread from plant to plant until they have damaged your whole garden or indoor plant collection, causing unsightly leaf damage or even death to the plant as a whole.

The key is a quick, effective treatment as soon as the problem is discovered.

spider mites yellow and black on leaf

What are Spider Mites?

Spider mites are a type of arachnid – the same class as spiders, scorpions and ticks – but they are very small (even large adults are only 1/50 of an inch, or about the size of the dot on a typed letter i) and not harmful, or even noticed, by humans… until they infest our favourite plants! Adult specimens range from a reddish-brown colour to a pale cream. Younger specimens look much the same as the adults but are of course smaller.

These mites live mostly on the underside of leaves, so they are difficult to detect at first, but since they live in colonies and multiply quickly, their effects are soon noticed. They poke through the underside of leaves and drink out the chlorophyl and other fluids, leaving a light, translucent dot on the top of the leaf. Enough of these little creatures on a leaf and it will dry up, turn yellow, and fall off. One good way to determine if you have an established colony on your plant, is to look for fine webbing around the edges of the leaves.  This is especially common in house plants, but can occur outside too, on strawberries, beans, melons, aubergines, tomatoes, many flowers and even trees.

Spider mites like hot, dry conditions best, so an indoor windowsill with no natural enemies about is a perfect place for them to set up a colony and multiply rapidly. In some cases, a species of plant-feeding mites will be accompanied by a species of mite that feeds on the plant-feeders, creating a miniature food chain, right there on your windowsill!

Spider Mites Life Cycle

Most mites last over winter as eggs, stuck to the leaves and bark of their host plants. They hatch in early spring, when temperatures rise, and leaves begin to turn green. The larvae are very tiny, six-legged creatures that last only a few days before moulting into nymphs, an eight-legged, still tiny version of their adult form. They will moult two more times as they grow, becoming adults after the final moult.

Female spider mites can produce up to 300 eggs in a couple of weeks after reaching adulthood. A new egg can grow to adulthood in as little as five days if conditions are favourable, and the hotter and dryer the weather is, the more prolific they are. A spider mite colony can produce several overlapping generations per year, with some of these new individuals moving from one plant to others by ‘surfing’ on air currents using their webs. It is important to dispose of dead or heavily infested plants carefully, so as to avoid infesting others.

How to Identify Spider Mites on Your Plants

The first sign that you have a problem will be tiny light spots on the leaves, usually yellow or light brown in colour, where the juices had been sucked out of the leaf from below. With more infestation, the leaves will yellow and dry up, sometimes falling from the plant altogether. The plant itself may stop growing.

As the colony establishes itself, you may notice fine webbing around the edges of leaves and between leaves and stem. This is when the problem is spotted most of the time. Shaking the leaves over a sheet of white paper or wiping the bottom of the leaves with a damp tissue, will tell you if there are specimens on your plant. In the first case, you will see tiny dots, like pepper, fall to the paper. In the second case, you will see brown and/or yellow smudges on the tissue.

Damage Caused by Spider Mites

Leaves become spotted and yellow, often dry, and may fall off of the plant altogether. This is due to the juices being sucked out of the underside of leaves by the spider mites. The loss of leaves and productivity within each leaf may cause a significant decrease in yield for watermelon, melon, and squash varieties. Plants such as beans and sugar peas can see damage on the actual pods as well. Spider mite damage is otherwise mostly cosmetic, though it can kill certain plants and is of obvious concern around plants grown for appearance, such as field roses, house plants, etc.

large plant with spider mites

Natural Solutions to Spider Mites

If you prefer not to use harsh chemicals on your plants, there are plenty of environmentally-friendly options open to you. Nature has its own way of limiting the spread of these little mites, so all we have to do is let nature have access to them, or give nature a little help, and the problem can be curbed.

Using Predators (the biological method)

Lacewings, thrips, ladybirds and even some other mites (such as Phytoseiulus persimilis) can greatly reduce the size of spider mite colonies, though they seldom wipe them out entirely. Using pesticides will reduce these natural predators and allow spider mite populations to increase unchecked, as they will move in as soon as the chemical has sufficiently diluted and can produce a thriving colony very rapidly. Regular, appropriate watering and use of mulch is also beneficial to keeping plants strong and better able to fight off the negative effects of infestations.

Predatory mites and insects for indoor plants can be ordered online. These can eat hundreds of mites in a day and are not dangerous or unsightly to people, plants or pets.

Using Essential Oils

There is some indication that chamomile, coriander, spearmint and rosemary oils are effective at killing the two-spotted variety of spider mite eggs and adults. A few drops in a spray bottle of water, sprayed onto the leaves, is the best method of application. Neem oil sprayed onto the leaves will also show some success in suffocating dust mites.

Get Them Hot Under The Collar

Hot pepper extracts sprayed onto plants showed some success. Bell pepper, jalapenos, chile and cayenne pepper extracts killed about 45% of mites in test conditions, and have been shown to reper mites prior to infestation.

Speculative Home Remedies

Three tablespoons of dish soap in a gallon of water is a high enough concentration to kill dust mites without being so high as to harm your plants. Spray this onto infested plants weekly, and rinse after a few hours.

Rubbing alcohol, applied to the leaves with a cotton wipe, can also kill spider mites. It is also recommended to rinse the leaves afterward with a water wipe.

In outdoor situations, spraying with a hose can physically remove many spider mites from a plant, but they will likely come back very quickly, and may be aided in spreading to other plants in this way.

spider mites webs

Using Chemicals

Pesticide Sprays

In order to properly apply pesticide sprays, you should invest in a professional lance sprayer. These are not overly expensive, and do a very good job of helping you get into hard-to-reach areas of the plants, and keeping the spray more contained to desired areas.

Be sure to cover the top and bottom of leaves evenly. Most eggs and mites will be on the underside of the leaves, but they can also escape danger by moving topside, so it is important to do both areas. Spraying when the lights are off is recommended, as the mites will be more active. Using a dimmer or a headlamp will help you be able to see what you are doing in such conditions.

Make sure there is good air flow through the room of area you spray, to prevent rot and other negative effects.

Fumigate with Vapourised Sulphur

Vaporised sulphur is very effective at killing and repelling a number of pests, including spider mites. It is best used in a grow room or other isolated growing situation, rather than in the home for houseplant care.

The vapour of this substance prevents the mites from feeding or reproducing properly, dropping populations very quickly.

Do not use it during the last two weeks of flowering.

How to Prevent Spider Mites in the First Place

Even better than killing off an already-established spider mite colony, is preventing the infestation in the first place. If you’ve just gotten rid of a colony, you’ll also want to prevent another from moving in and taking its place.

When you bring a new plant into your home, check for mites by placing a white paper underneath the leaves and tapping them to check for mites. You can even do this before purchasing the plant.

When you have the plant at home, with no sign of mites falling onto the paper at the shop, place it away from open windows or vents, as this is often how the spider mites enter and infest a new plant. Dusting leaves once a week can also keep new colonies from starting.

Spider mites prefer dry conditions, so keeping your plants well-watered is also beneficial.

Spider Mite FAQ’s

Is it better to get rid of the infected plant?

If an infestation is advanced and has caused a lot of damage to a plant, it may be most effective just to rid yourself of the plant altogether. You should then apply preventative measures to your other plants, especially in the vicinity where your infested plant was.

How long does it take to get rid of spider mites?

Even for infestations that are not considered severe, it may take three or more weekly applications to take care of the problem. Of all of the methods, predatory mites is probably the quickest, as these consume hundreds of mites a day and there is no need to reapply or wait for concentrations to fade – they work for you all day long, every day.

What are the most common plants infested by spider mites?

Spider mites are not picky eaters. They will live and thrive on hundreds of plant varieties. In the outdoors, they like melons, strawberries and fruit trees, and indoors they prefer ornamental flowers and shrubs.


Enjoyed that? Good!

If you need some hydroponics equipment, then you can shop the Acorn Horticulture range here.

Our range includes grow lights, pest control, propagation, and more.

COVID-19 | A Message To Our Customers

In light of the recent measures set out by the government, Acorn Horticulture has taken the step of temporarily closing our doors for business, with immediate effect.

As always, the health & wellbeing of both our staff and you our customers remains our priority. The dynamic situation means we will be assessing daily and will continue to keep you informed.

Whilst we’re sorry we won’t be available to serve you face to face as we have been for over 10 years now we’ll still be available on the store number 0114 2458581 to help where we can and our website remains open for business. Although you may have to allow a little more time for delivery in some cases as our delivery partners are extremely busy.

We’d like to thank you for your continued support and patience during these challenging times and look forward to welcoming you back to our store as soon as we can.

Stay Home & Stay Safe

 

What is hydroponics?

The term hydroponics came about in the USA in the early 1930’s to describe the growing of plants with their roots suspended in water containing mineral nutrients. Derived from the Greek words for ‘water’ – hydro and ‘to work’ – ponos, hydroponics literally means ‘working with water’. The term has however gradually become broadened to describe all forms of gardening without the use of soil.

The use of hydroponic’s in history dates back to the Hanging Gardens of Babylon. The Aztec Indians had a system of growing crops on wooden rafts in shallow water.

You can still see some of these floating gardens in and around Mexico City. Further developments in hydroponics did not start taking place in Europe until around the 1850’s when a German scientist, started using nutrient solutions to study the nutritional requirements of plants and was followed by Sachs in 1860 and Knop in 1861 who made studies of nutrient elements in water solutions. They were able to grow plants in nutrient solutions made up from mineral salts eliminating the need for soil.

Research on the nutritional requirements of plants continued through the 1870’s. By 1925 practical applications of hydroponics were being made in the greenhouse industry. The next decade was to see extensive development as researchers became aware of the potential of growing hydroponically. In 1930 Gericke produced the first commercial hydroponic unit in the USA. Later during World War II the American forces in the Pacific grew vegetable crops hydroponically for quality foods aboard the ships. The commercial use of hydroponics spread throughout the world but it was the development of the N.F.T. system by Dr Alan Cooper in the 1970’s, along with improved nutritional formulations that made the hydroponic growing of a wide range of plants commercially viable. Since then automatic control systems have become available as well as digital testing equipment which has opened up the field of hydroponics to the home gardener.

Hydroponics has come a long way since the Aztecs. It has become an essential method of growing crops in areas of the World where water is precious and land useless for field growing. Water care and land care is now legislative in many countries in the World, so with well managed hydroponic crops we can keep producing high quality produce which is environmentally friendly and sustainable for the future in all areas of the world.

For more information on hydroponics and indoor grow systems, speak to our sales team here or call 0114 245 8581.

An Introduction to Hydroponics

Introduction to growing

By Acorn Horticulture

So you decided to take up the wonderful hobby of indoor growing but unsure where to start?? We have all been here at some stage; dazed and confused at the many different set ups available, the different mediums, the many different nutrient companies that all say their product is the best on the market bar non… Well there’s a very important part of growing that many seem to overlook before they choose their method and their range of nutrients, your environment.

The Set-up
The first decision to make is where to set your area up. This decision rests entirely on you and what space/resources you have available to you. There are some things to consider when making your choice:

1. Do you have enough power outlets for what you require? Lights, air pumps, extraction and intake fans, air circulation fans, growing method or system (a lot of automated systems require power).

2. Do you have access to fresh air for your intake? This is very important as plants require fresh air to perform well (the air contains carbon, nitrogen and moisture which your plants need) and an outlet for your outtake to expel warm air from your grow room.

3. How easy is it to get to your water supply?

Lets talk about ventilation a little bit.

This is one of the most important factors in your set up which is often overlooked, adequate air movement in and out of your growing space. Now the size of your room will dictate the size of your fans you require. Most indoor growers use a larger outtake fan than intake to create a negative pressure in the room and ensure all waste air is dispelled through your exhaust. As a general rule of thumb the air should be exchanged in the room at least once every 5 minutes. This however doesn’t take into account lights in the room (lights cause major heat) or pressure from the amount of ducting used (reducing the efficiency of the intake and outtake fans) so more volume of air is required to be moved to compensate for these factors.

If you’re unsure about what fans to use for your set up, email us, call us or come into the shop and have a chat with our helpful staff, they will be able to give you advice on what sized fans are required for the size of your room and how many lights you are using.

An important point I would like to point out – Carbon makes up an important part of a plants growth. This is a nutrient that is often overlooked or even forgotten about entirely!!! The plant takes in carbon through tiny little openings on the leaves called stomata. Without proper exchange of air in your grow room the carbon will be at a minimum therefore hindering your plants growth!

Spectrum and strength of lighting required
This is another massively important factor for your growing environment, lights. It’s a well known fact that plants cant grow without light as its a major part of their food source (via photosynthesis) and as plants are used to growing outside in the sun (a major source of light) they are going to need something a little stronger than your average house lights.

Most indoor growers use HID (High Intensity Discharge) lighting which work great for the required needs of plants. There are a few different types of lamps used but dual spectrum lamps are used most commonly, blue and red (there are dual spectrum lamps available that deliver both.) Blue (Metal Halide Lamp) is used more for the vegetative stage and red (High Pressure Sodium) is used more for the flowering stage although most growers tend to use the dual spectrum lamps as they put out both spectrums of light which improves overall growth and quality of plant and of course saves a few pounds in only buying one lamp.

There are many other lights on the market today like the fluorescent, LED and plasma to name but a few.

Compact Fluorescent Lighting (CFL) is used by hobby growers and professionals alike for many different reasons ranging from vegetative lighting to supplemental lighting helping HID’s in flower.

The Advantages of fluorescent lighting:

• Low heat output (the bulb gets slightly hot but is no comparison to a HID bulb)
• Low energy use (they come in 55w strip lights, 125-250w cfl lamps and T5 units with multiple strip lights)
• Broad use of light spectrum

The disadvantages of fluorescent lighting:

• Much lower power output than HID (not stand alone lights for flowering).
• Very low canopy penetration.

LED’s are growing more and more popular as alternatives to HID lighting although they haven’t surpassed them as the choice for growers worldwide.

The advantages of these lights are numerous:

• Low power usage
• Produce a broader spectrum of light.
• Give off minimal heat

The disadvantages:
• Lower humidity significantly
• Less canopy penetration than HID.
• Much less power output than HID (subsequently less yield)

Plasma lighting is still in its infant stage although there are a few of companies that make them (Gavita being among the most successful) they have a long way to go before they will reach the hobby growers room. These produce light as close to the spectrum of the sun as possible so have a major advantage over it’s rivals but costs significantly more too.

Advantages of plasma lighting:

• Full spectrum lighting
• Low heat output

Disadvantages of plasma lighting:

• Expensive (as its still in new stages of development) £995 currently
• Less power output than HID

This is just a few simple idea’s on what you need to set up your grow room before you attempt to grow anything indoors. Remember, environment is the number 1 factor that decides whether a grow will be successful or not. Think of it like your own working conditions, if you’re too warm your work will suffer as you’re not in your comfort zone. Too cold and you will almost stop working as your fingers and toe’s begin to seize up. Plants are no different in this respect, they need to be in their perfect environment to perform properly.

In the next section we cover the different types of automated grow systems, their advantages and disadvantages and which will work best for you.

Acorn Horticulture.