lighting recommendations

[saltyreef]

I have about a 70 gallon aquarium. dimensions are 48 long x 21 wide x17 high. I am gonna go with metal hallide i believe. probably 250W 20k. Would i just need one or would I need more. If you think 175's would work better let me know. I am starting with just FOWLR but will soon be getting into corals and eventually SPS. I would like to buy the proper lighting to start so i don't have to uprgrade. Do i need any special light for the live rock to start with? Thanks guys

[danny zubot]

I'd recommend two 175 watts. Your tank isn't that deep so 150 to 175 watts will be okfor pretty much all corals IMO. At 4 feet you'll want two bulbs for sure, to achieve a good spread of light. IMO, a single bulb can do no longer than a 36" tank. Of couse if you have supplimental lighting, it changes things a bit. I've seen people use a single 250 on a 90 gallon tank, but they have 4 foot florescent bulbs added to it.

If you ever want to upgrade to a deeper tank in the future, you might consider going with higher wattage lighting, like 250-400 watts.

[Quagmire]

I agree with Danny,that 2 lights are better than one,and that 150 or 175 are fine with that depth.But as far as "Need" you can get away with 1 MH on a 48" tank,but for SPS you will want to keep them to the middle of the tank nearer the light,and have your less light loving corals closer to the sides.Rule of thumb for MH is 2'x2' for each bulb.But again it depends on what corals you want,even SPS very from 1 to another.