Under Canopy LED Grow Lights

What under canopy lighting does

Once a canopy is mature, the top fixture's intensity drops quickly as it works down through the leaves, and the lower third sees only a fraction of the light the tops receive. Under canopy lights — also sold as UCL, understorey or side lighting — sit below or beside that growth and hit those sites directly. They add to a main fixture; they never replace one.

Where it makes a difference

How much you get from it depends on how deep the canopy is. A short, well-trained canopy has almost no shade to correct; a tall or dense one has a lot. Heavy defoliation leaves fewer shaded sites to rescue, so those rooms usually see a smaller gain than a deep, unthinned canopy.

Our range

For a small tent, the slim AC Infinity Ionbeam S11 (30W, 28cm) and S16 (42W, 40.6cm) fit between plants. Larger rooms step up to the ULight 110W Pro bar or the Hi-Par Understorm 200W with a manual dimmer, and the top of the range is the Digi-Lumen Extreme Under Canopy 200W and Side Bar 250W (2 x 125W). Digi-Lumen also sells adjustable stands in pairs, so you can set bar height under the canopy.

Fitting under canopy lights

1. Mount low and point up. The job is to light the growth your top fixture never reaches. A bar at canopy height just copies coverage you already have.
2. Watch the heat and the leaves. A bar parked against foliage can scorch. Leave a hand width of air and inspect the leaves after a few days.
3. Keep them clear of runoff. Irrigation runoff and fixtures at floor level do not mix. Put bars on stands instead of leaving them on the tray.
4. Add the watts to your budget. These watts sit on top of the main light — check the circuit before you hang several bars.

Figure the running cost on the Grow Light Electricity Cost Calculator. Main fixtures live in LED grow lights.