I have a tank with only plants in it. Can i keep the light on 24/7 for maximum growth? i know you can do this with some "land" plants (cough cough, i wont say which ).
I'm not totally sure, but i don't see why it would be a problem for the plants, however wouldn't the tank get very hot if the tank lights were left on all the time?
Cough cough no you can't do this with those land plants, you're just wasting electricity. No plant will benefit from 24/7 light ... all plants need time to respire its part of their cycle.
As the poster above mentioned, the only thing you'll get from 24/7 lighting is algae.