Quote Originally Posted by Permabaked
True but don't people only use MH bulbs for the last couple weeks of flowering because of the additional UVB it provides? Maybe he should add another set of plants to his experiment that only receive UVB at the very end.
people only use MH during the last two weeks of bloom because they get bigger yields with HPS and no other reason. i've read a case study where a grower grew two identical crops, one at 4500' and one at 9000' elevation. the crop at 4500' had about 25% more yield, but less trichs.


-shake