What can I grow under a T5 Hydrofarm 4' x 4 bulb light fixture?

[rosemadder]

In the meantime though, you can probably use our numbers as an estimate to go by. Very similar lights to yours.

Artificial light is a little funky though. It may count for less depending on the actual spectrum of the bulb, or it may count for more since artificial lights are so steady for long periods while natural light is not.

I have a couple of old 54-watt 6500k compact fluorescents that I put over my windowsill orchids. At the leaves, the extra light is only about 600fc, but my vandas have noticeably perked up. No idea yet if they'll ever bloom, of course.

[DTEguy]

Originally Posted by rosemadder

the extra light is only about 600fc, but my vandas have noticeably perked up.

I understand that different bulbs may vary, but from my limited experience with my T5's PAR, about 30% of the reported footcandle is all I needed--under my 14 hours light exposure.

So, the 600fc that you provided "could" be equivalent to a 2000 fc (at peak) sunlight.