Can you have too much light?

Busy building a grow room in a shed. The local school is changing from t5 to LED, and are literally throwing away hunnerds of 2’ sq, four x 28w tube T5 units away. I’ve nabbed 18 units.

Each T5 unit 4x28w bulbs totalling 112w per unit and the units are 2ft sq.
Hypothetically: If grow room was 8ft long x 4ft wide (32sq ft) and about 4ft high and the walls and roof were made up from these t5 light units. I’m growing autos and they are short growing to about 32 inch 2 1/2 ft or so.
(Let’s not get hung up about the frame, how to get in and out and if the plugs can cope)

Two rows of T5 fittings making up a 4ft wall:
Long walls and roof would have 4 x 2 units = 8 units each 3x8= 24 units x 112w =2688w
Short walls 4 units each 8x112w = 896w
Total 3,584w 112w/sq ft

One row of T5 fittings making up a 4ft wall:
Long walls would have 4 and roof would have 8 units each 16 units x 112w =1792w
Short walls 2 units each 4x112w = 448w
Total 2240w 70w/sq ft

I’m interested to know if the plants would like all that light from all angles, its fluorescent so not too hot and burning the plants with radiated heat is unlikely. The technical issues of moving walls as the plants grew would be interesting to overcome.

Is this too much light?
Is there too much light from the walls and would this cause problems for the plants?


Welcome to the forum!!!

Here ya go @dbrn32

I don’t believe it’s too much light, but I would put majority of light at top of space. The plants don’t really do a great job of absorbing light energy from the underside of their leaves.

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Thanks for the welcome and the advice.
I’ll start construction this week and post post photos