Grow Tent Setup: How to Set Up a Grow Tent, Step by Step

A grow tent is a light-tight, reflective room in a box, where you control the light, air and temperature. This guide takes a first tent step by step, from choosing the spot to a test run with everything on. It also covers what our grow tent kits include, and what to add.

What goes in a grow tent

Step 1: choose the spot and build the tent

You need a floor that can take a spill, a socket within reach, and somewhere for the stale air to go, such as a window or wall vent. Our tent size guide says to leave 20 to 30 cm around the tent for the fan, ducting and zips, and that a 200 cm tall tent needs a little more height than that to stand up.

Build the tent where it will live: frame first, then the fabric over it. Then protect the floor with a Flexi-Tray: 10 cm deep, in 80, 100 and 120 cm squares.

Step 2: hang the light

The fan and filter hang from the same roof bars, above the light, so fit them first (Step 3) and check what the bars can carry: the Secret Jardin HS120-R2 page gives up to 30 kg.

• Rope Ratchets: their page gives 34 kg each, and recommends them for heavier items such as carbon filters.
• Easy-Rolls (pair): cord pulleys that hold up to 5 kg each, 10 kg a pair. For scale, the Maxibright Varidrive 360W LED weighs 2.9 kg.

Follow the maker's card for height: our LED wattage guide says usually 30 to 45 cm above the plants at full power, higher over seedlings or when dimmed.

Step 3: fit the extraction, the intake and a clip fan

Sizes first: see our fan and filter sizing guide.

1. Join the filter to the fan. The fan pulls air through the carbon filter, so its inlet faces the filter. Use Fast Clamps (their page also recommends tape for air-tightness), or a short length of ducting and two ducting clips.
2. Hang them inside, at the top, where the warm air collects.
3. Duct it out. Run ducting from the fan through a top port to the outside: short, straight, pulled out fully, a clip on every joint.
4. Let fresh air in. Open a low vent, ideally opposite the fan. With the fan running the walls should pull in slightly: that negative pressure stops smell leaking from the zips. If they pull in hard, open another vent or turn the fan down.
5. Add a circulation fan. Clip one to a pole so the leaves move gently: the Maxifan Clip Fan 200mm has an adjustable head, the AC Infinity - Cloudray Clip Fans several speeds.

Step 4: timers, contactors and cables

Only the light goes on the timer: the extractor and clip fan run day and night. Our getting started guide gives 18 hours of light for vegetative growth, usually 12 for flowering. A contactor is a heavy-duty relay that a timer switches, so the contactor carries the load, not the timer.

• Optimum Timer (formerly Grasslin): a segment timer with 15-minute steps. Its page says it is limited in load: it controls light cycles when used with a contactor or relay.
• Maxiswitch Quad Timer: runs up to four grow lights; its page says it is built for high power loads.

Not sure your timer is rated for your light? Ask us first. Add up the watts on each socket and extension lead, and keep within its rating. Keep plugs, timers and leads off the floor, and let each cable dip below its plug (a drip loop), so water drips off before the socket.

Step 5: pots, feed, a hygrometer and a test run

• Pots, medium and feed. The getting started guide calls good soil the easiest place to begin; coco needs a feed made for it. See the pot guide, or our hydroponics page to grow without soil.
• Thermometer-hygrometer. Hang one at plant height, such as the budget Digital Hygrometer; our grow tent humidity guide compares three.

Before planting, run the tent with everything on for a full day and night:

1. Check the timer switches the light on and off.
2. Darken the room and look for light escaping at zips, ports and seams.
3. Read temperature and humidity at plant height with the light on, then off. Our airflow, temperature and humidity guide gives 22-26°C and 55-70% humidity for vegetative growth, 20-25°C and 40-55% for flowering. An empty tent reads drier than a planted one, so treat the humidity as a starting point.
4. Too hot: turn the fan up or dim the light. Too cold: see heaters. Too damp or dry: see grow tent humidity.

Complete grow tent kits

Each kit is a Budbox Lite tent with LED lighting, an Air EC inline fan with its manual speed controller, a Rhino Hobby filter, 5 m of combi ducting, three ducting clips and a timer.

Choose by floor space: our tent size guide gives the plants each size holds.

No kit lists rope ratchets, a clip fan or a thermometer-hygrometer, so add those; only the two larger kits list an extension lead. Pots, medium and feed are an optional bundle, such as the 4-Pot Soil & Nutrient Bundle: four 12 L fabric pots, saucers, Plagron Light Mix Soil, a pH test kit and Intense Nutrients feeds.

Quick answers

What do I need for a grow tent?

A tent, light and hangers; a fan, carbon filter and ducting; a clip fan, timer and thermometer-hygrometer; then pots, a medium and feed.

What is in a grow tent kit?

Ours have a Budbox Lite tent, LED light, Air EC fan, Rhino Hobby carbon filter, ducting, clips and a timer. Add hangers, a clip fan and a thermometer-hygrometer.

Should the walls of a grow tent pull in?

Slightly, yes: the pressure inside is a little lower than outside, so any leak at the zips is inwards and the air leaves through the filter. If the walls pull in hard, open another low vent or turn the fan down.

More Growers' Guides

• What size grow tent?
• Fan and carbon filter size
• Grow tent humidity
• Grow room running costs
• Growers' glossary

Not sure what you need? Call the shop on 0117 971 3000 or pop in to the Bristol store and we'll help you pick.