400 watt mh for 75 gallon? Need advice...thanks

[bassetbros]

would a 400 watt mh be too much for a 75 gallon? Can you have too much light? If I purchase one, I'll probably build a hanging canopy with a couple of actinic 40 watt NO.

If I build a hanging canopy, would I need a fan?

With a canopy that rests on the aquarium, would I need a fan?

Would that much light "sunburn" corals and other stuff on my live rock?

Do you think any fish I get would be "spooked" or be a little shy because of the mh?

I just found a deal ($90) and have been pondering.

Thanks and God Bless,
Basset

 

[fishfreek]

You need two MH bulbs for a tank longer than 3' in lengh. This is because the MH bulb unlike florecent bulbs emit their light from a single point and the light is only really effective as reef lighting for a 2' square area. So for a 75 gal tank or any other 4' long tank you should have two MH fixtures. Unless you was looking to keep very high light required coral and clams you can do with a pair of 175W MH bulbs or a pair of 250W MH bulbs. Going with a pair of 400W MH bulbs would be overkill for a 75 for all but the most light hungery inverts.