2 175 watt enough light?

[Cheapreef]

Would 2 175 watt MH be ok in a 75gal depth of 20". This would be for a maxima and a derasa. Or should i stick with the single 400watt i have now. The reason i ask is i am building a new hood and have 2 175watt MH and ballasts sitting doing nothing. This would also give me a better spread of light. What do you guys think? Oh i forgot, i have a 4-5" DSB and the lights will be about 4" off the water surface. I just messured the top of the water is about 14.5" deep

Thanks
Clinton

 

[Physh1]

I would see no problem doing that swap. With only 15 or so inches of water the 175 will suite that just fine.

Cameron

 

[BonsaiNut]

I kept clams for years under dual 175w with VHO actinics. Keep them towards the top of your tank and you'll do fine (from a lighting perspective).