You can keep them alive with regular flourescents, but they thrive under power compacts. In 3 months with PC's my mushrooms have doubled, both in size and number. The pics I have posted are right when I got my PC's, I'll update them soon so you can see the difference.
I HAVE TWO 40 WATT FLO AND I'VE BEEN ADDING CAROL-VITE, CALCIUM AND JUST STARTED IODIAN. THE MUSHROOMS I HAVE JUST APPEARED ONE DAY AND I WAS HOPING TO GIVE THEM A BOOST. DOES HIGH NITRATES AFFECT THEM (50 PPM)? YES I KNOW, SPELLING SUCKS.
I just use 60 watts VHO and 60 watts Actinic in a 6 ft. tank.My Ricordia is hardier than my mushrooms.I have found something that will kill Mushrooms and not Ricordia.That is that Invertebrate safe Kick Ick.Polyps and Ricordia doing fine.I use Reef Complete,Kent PH Buffer and Iodine.
I think your lighting might be a bit too low. How large is your tank? Your mushrooms might survive under the lighting that you have, but they will not thrive. I had mushrooms under normal output fluos. They didn't do much, but when i changed to high output lights, I saw immediate improvements.
Although mushrooms are tollerant of 'not so perfect water', I feel that a nitrate reading of 50ppm is pushing it. Try bringing it down. I remember reading somewhere that 40 ppm is as high a mushroom would tollerate.
A combination of very low lighting and higher nitrates is not helpful in the long run. Bring down your nitrates and consider purchasing a high output fixture.