Summer is a-coming!
Indoor growing can be a very absorbing hobby. However, it does come with it’s own fair share of obstacles that a grower will have to overcome in order to have a successful crop. One of the big ones is: how to to keep a grow going successully during hot weather?
Most people love the Summer: the warm weather, the long light evenings and spending time in pub beer gardens make a welcome change from the Winter months. However, when the weather turns warm, an indoor grow-space with it’s hot lamps can quickly get so warm that it is detrimental to plant growth.
Any temperature above 28C is going to start to see your plants suffering. That temperature can be surprisingly quickly reached when the outdoor temperature is already at about that level.
Fortunately, there are a few tactics and products out there that can help. In this article, we’ll take a look at what can be done to make sure that your plants, and consequently your crops, don’t take a big hit.
If you don’t already have one, you need to make sure that you have an effective extraction system. They are ideally required, even when temps aren’t going through the roof. Plants use the CO2 in the air, and once it is used up they will be unable to grow any more. An extraction system makes sure that the air is being changed continually, with the CO2 depleted air being replaced with fresh air with natural levels of CO2 in it.
Installing a quality extraction system will also draw in cooler air, replacing the hot & stale air in the grow-space. An oversized one, together with fan-speed controller will give the grower plenty of lee-way to have it running on low during the winter months (when less cooling is required) and turn it up during hot weather to replace the heated air much more quickly.
Light Systems with an Adjustable Ballast
Turning down the wattage being fed to your grow-lamp will reduce the amount of heat that it produces. This helps keep your grow-room temperatures down. Many digital ballasts have the facility to run a 600 watt lamp at 400 watts or even lower it to 250 watts in times of hot weather.
Our favourite brand is the Adjusta-Watt range of ballasts. They have the facility to turn down the wattage being fed to your lamp, they’re superbly made, plus they come with a host of safety features and an overdrive setting to boost the light output from an aging lamp (this overdrive setting will produce even more heat, so it would be for use in times of cooler weather).
Or if you are looking for a budget option for the moment, take a look at our tru-6 digital light kit. It comes with a lamp, reflector and a digital ballast that kicks out a genuine 600 watts, all for just £89.95 (at time of writing). Just like the adjusta-watt, the power output is switchable and it even boasts a similar super-lumen boost feature to get the last bit of life out of an old lamp.
However, if it’s a top-of-the-range adjustable light system that you takes your fancy, look no further than the Dimlux Pro range….
Dimlux Pro Lights
Dimlux produce a professional range of 400V lights that are very similar to the Gavita Pro range – with one exception – the Dimlux Expert range can be connected together via a controller and a leaf temperature camera, and then they will automatically dim (when required) in order to help maintain a particular temperature. In this way, if your grow-space becomes unmanageably hot, the lights will turn themselves down in order to produce less heat.
As well as that, Dimlux Expert lights are premium quality and use a 400 Volt system just like Gavita Pro systems (but both systems run off UK mains 230V supplies) and are very efficient, producing more μmols of PPFD (Photosynthetic Photon Flux Density) per watt of electricity consumed. Plus, if you use the controller, it will control the lights-on lights-off switching for you too.
The Opticlimate full climate control system
I don’t think it would be a stretch of the truth to say that soon, virtually every grower will want one of these. Opticlimate full climate control systems are new on the market, and perform a marvellous job of keeping your grow-space at the perfect temperature and humidity. The units contain an air conditioner, an air heater and a dehumidifier all in one. They feature a temperature probe, a humidistat plus a light sensor. The Opticlimate control units automatically keep your garden at the perfect temperature and humidity level to maintain the ideal VPD (Vapour Pressure Deficit) so that the plants in your garden are always photosynthesising optimally and are at a very low risk of mold attacks.
Our customers that use one of these devices never need to worry about their garden temperatures ever again, and the benefits in terms of yield can be anything up to an extra 25% over and above what can be achieved with a well-tended grow but with a less well-controlled environment. However, they are designed not to be used with an extraction system (i.e. they create a “closed-loop” grow space) with air neither entering nor leaving. Because of this, CO2 supplementation is an absolute necessary when using an Opticlimate.
Even if you manage to successfully keep control of the air temperature in your garden, you could still run into problems with the nutrient solution in your reservoir getting too warm. As your feed-water drifts over 20C, you could start running into problems. Warm water is not capable of holding as much dissolved oxygen as cool/cold water. Plus, warm water is a breeding ground for root diseases such as the dreaded pythium root-rot.
As any grower that has had a problem with root-rot breeding in their hydroponics system will tell you – once it has taken hold in a system it destroys plants in a couple of days, and getting rid of out of the system is a nightmare. It is much better to prevent it ever taking hold in the first place. A reservoir chiller circulates the nutrient solution through itself and keeps the water at the right temperature saving you a whole lot of headaches.