mulron said:IMHO, I'd put the at the bottom of the tank else they will "bleach" which in mushroom terms means turn brown and not that kool green color. They are pretty tolerant to many conditions but med to low light is prefered and low flow.
Hope this helps.
Thats not always the case. Now granted I acclimated mine to the light, but I have red, watermellon, and purple shrooms at the top of my tank and they are multiplying like crazy...and they open up huge.
Edit: I forgot. They are under a pair of 175watt 10k m/h bulbs and 2 110vho actinics.