Your mushrooms definetly will react to two 175w halides, and not necessarily for the best. They prefer indirect lighting. I would place them on the bottom of the tank and out of direct way from the halides. They could be shaded by some plants, live rock or another larger coral.
Mushrooms are easy. They are quite forgiving if your water quality is not up to par. Outside of not liking direct strong light, they do not like strong water currents. After your tank becomes established, 8 months to a year, your mushrooms, if happy, will become weedy as they will sprout up everywhere (According to books I have been reading and other posts here). Apparently they become a bother because, despite their beauty, they sting neighbouring corals.
I also have been supplementing with iodine. They seem to respond well to it. Goog Luck with your shrooms! TT.
