Burning & Bleaching

[mimi]

I have a 75 gal reef. The tank measurements are 48x18x18. I have been told that the best combination for lights are a MH/VHO combo for keeping SPS, LPS and clams. I thought to have 2-250w MH and 2-48" 110w VHO's (one 50/50 and one actinic). For a total of 720w of light; with 2 fans in a retrofit.
But I am very afraid that this lighting combo will burn or bleach the few soft corals, mushrooms and anemones I already have in my tank. The tank is only 18" deep with about a 2" sand bed. Will this be too much light for the corals I already have? Should I go with 2-175w MH instead? 55w PCs instead of VHOs?
Please help,
MiMi

[Chuck S]

HMM I have a 120 with 2 400watt halides and 2 110watt actinics for a total of 1020 watts over the tank. I doubt you that light is too much if you really want to house SPS and clams. You will however most likely have to move some lower light loving organisms lower in the tank. You will also have to slowly over 2-3 weeks acclimate the animals to the new more intense light.

[tendar]

Go with the 250's. The mushrooms should be moved to a less lite area or even under a over hang would be best. The anemone will love the new lights once acclimated as should most all of your current corals other than the mushrooms. Just make sure to slowly acclimate them to the new lighting.