- 1 Do I really need a grow tent?
- 2 Ok so I need a grow tent, what should I be looking for?
- 3 Height
- 4 Thickness
- 5 Strength
- 6 Reflectivity of interior lining
- 7 Other Features
- 8 Recommended Grow Tents
- 9 Grow Tent Accessories
- 10 Ventilation systems
- 11 Extractor fan size
- 12 Carbon filters
- 13 Intake fan
- 14 Ducting
- 15 Recommended Ventilation Systems
- 16 Temperature and humidity sensors
- 17 Timer Switches
Do I really need a grow tent?
Probably the very first question that an indoor gardener will ask herself is where can I grow my plants? Since most plants grow best at a specific temperature and humidity range as well as under specific periodic bright lighting arrangements, a designated enclosed space is needed if you want your plants to grow undisturbed to their full potential. If you have the space available, you can allocate a room to become the grow room. If, like most of us, you don’t happen to have a spare room just lying around, then the next best option is the grow tent. Grow tents offer convenient and practical ways to create the perfect environment for your plants, allowing you to control things like temperature, humidity and light precisely, thereby optimising plant growth. They also have the added benefit of isolating the growing environment away from anyone else so that people in the vicinity are not disturbed by conditions in the growing environment such as its intense lighting.
Ok so I need a grow tent, what should I be looking for?
There are several factors that are important to look at when purchasing a grow tent.
It is important for your plants to have enough headroom for them to grow, so you really need to know how they will perform beforehand so that you can get the right size tent to keep them healthy and maximise yield. Importantly when calculating the size of the grow tent, you will also need to take into account the minimum distance away from the grow light that the plant canopy needs to stay in order to remain healthy. You don’t want your plants growing into the lamps and then dying off due to the excessive heat given off by them. Importantly, if you are using LED grow lights which generate much less heat, the plants can grow much closer to the light source than with other types of lighting such as HID lamps. Generally speaking, when choosing a grow tent, taller is better (as long as your room ceiling is high enough to accommodate it) with the added advantage that you won’t have to squat down as much to access you plants with taller grow tents.
Thickness of the grow tent fabric is a factor in how robust the grow tent is and how long it will last. In addition, the thicker the material, the less light, odours and noise will escape from the grow tent. Thickness is usually given in Denier (D). The higher the Denier number, the thicker the material fabric and generally the higher the quality of the grow tent. The most common thicknesses available are 1680D, 600D, and 190D. Grow tents with a fabric thickness of 1680D can be rather expensive whereas those with a thickness of 600D often represent the right balance between recommended thickness and price.
There are several things to keep in mind here. First and foremost, is the frame. This can be made out of plastic or metal. Generally speaking, metal frames are better, and the thicker the poles, the more sturdy the tent. In addition, the corner brackets that hold the frame together ideally should be made of metal although plastic ones will suffice but will have a shorter life. The final durability characteristic to look out for are the zippers. The zippers zip closed the access points to the grow tent and these need to be of high quality as you will be regularly opening and closing the tent. If you have been unlucky enough to have a zipper break, then you will know how difficult it can be to keep the light, odour and noise completely isolated from the outside environment without a functioning zipper.
Reflectivity of interior lining
For the inner lining of the grow tent, you generally have 2 choices: Silver Mylar or a white surface. Silver Mylar provides a better reflective surface than white-lined tents and since heat is rarely a problem with LED lighting, this is the recommended lining of choice for your grow tent. However, Mylar-lined tents can get excessively hot if grow lamps other than LED grow lights (eg. HID lamps) are used, so white-lined tents will perform better when using traditional grow lighting.
Spillage Protection: Ideally the grow tent will have a waterproof floor covering or tray to protect against accidental spillages, which happens to almost everyone at some point. It is also especially important when working with hydroponic systems, since blockages and other mishaps can lead to nutrient solution overflow.
Recommended Grow Tents
Grow Tent Accessories
So you finally have your swanky new grow tent, you’ve assembled it together with the grow light that you’ve purchased after reading all (ok, ok, SOME) of my other stuff on LED grow lamps, and now you’re itching to position your plants inside the grow tent and set it on its way. But not so fast! You are going to need a few other pieces of kit which are essential tools in keeping your plants healthy and vibrant throughout the growing cycle. One of the most important is a ventilation system for the grow tent which generally consists of ducting, an inline extractor fan and a carbon filter. The ventilation system serves two functions: first, it changes the air within the grow tent to keep it fresh, mostly to keep a consistent supply of CO2 for the plants to use, and secondly, it removes excess heat. You can get away without a ventilation system in a very small grow tent assuming you are using LED lights, but in larger tents or with more traditional forms of grow lighting, a ventilation system is essential. If a ventilation system is not used, plant growth may be inhibited by inadequate CO2 levels and increased temperatures or humidity which are sub-optimal for plant growth (assuming the plants survive in the first place!). And to really top it off, increased temperature and humidity within the grow tent can also lead to mould formation and plant rot, stuff you definitely don’t want going on in your grow tent.
Extractor fan size
Ventilation systems come in several different ‘sizes’ to cater to the different-sized grow tents and you will need to identify the system that will work effectively for your grow tent. In order for a ventilation system to be effective, it will need to completely change the air within the grow tent, at the very least, every 3 minutes or 20 times per hour in order to keep the CO2 that plants need at optimal levels. However, you will want a ventilation system that can do much more than that in order to remove the excess heat given off by the grow lighting, especially if more traditional forms of grow lighting are used.
The carbon filters are necessary to prevent the odours from the plants and growing media from entering the room housing the grow tent but they are only important if you are venting the air of the grow tent directly into the room. However, if it is being vented to the outside (assuming you are not annoying the neighbours with the exhaust), then the filter becomes unnecessary, although in the UK we don’t always have the luxury of easily installing an external vent.
An intake fan can also be installed to force fresh air into the tent but in many cases, it is unnecessary if your extractor fan is working optimally as the negative pressure created by air extraction will force air into the tent via the intake openings, unless of course you have a large grow tent.
The extraction ducting should be positioned so that air is extracted from the top of tent to remove warm air first. The fresh air intake openings should be positioned on the opposite side, towards the bottom of the grow tent, so that fresh air flows up through the plant canopy towards the exit.
Recommended Ventilation Systems
Another important accessory is a temperature sensor which is essential to make sure that your plants stay within their optimal temperature range. This is especially important if you end up using grow lamps such as HID lighting that generate a lot of heat. If you have a household thermometer that you can position within the grow tent, then that should suffice but these days for a few pounds, you can get an all-singing, all dancing digital sensor which also provides you with humidity data that you need for optimal plant growth. For ideal plant vegetative growth, the temperature target range that you will be aiming for will be 21oC -28oC. As for humidity, you are looking for a relative humidity (RH) of 50%-80% as the target range. Black Orchid is a well-known brand in the hydroponics / indoor-grow community and they have a useful temperature and humidity meter specifically designed for us indoor gardeners (see picture on the left).
Another piece of equipment that you will be hard pressed to do without is a timer switch. For LED grow lighting, your bog-standard timer switch should be fine to use. One of my favorites is the Silverline Plug-In Mechanical Timer (see picture on the left) due to its simplicity, excellent value, and most of all, its lack of noise, unlike many other brands of timers that can produce an incessant clicking noise.
However, LED grow lighting is not yet used by everyone so it is important to mention that with HID lighting, you should NOT use your normal timer switch that you might have lying around the house because it has not been built for such high loads. A timer switch specifically designed for HID lighting (such as the one in the picture on the right) is essential.