HOW HIGH

[m and m]

I have a 75g tank 20" deep and two 400w MH i was wondering how high should they be off the top of my tank i will also be getting two strips of t5's i would like to be able to keep sps and clams at the bottom thanks

 

[RichT]

400W is a lot of light for 20" deep tank. I'd say 12" or more off the water. You have a chiller? The T5's, from what I've read, need to be around 3" - 5" w/ SLR's to be really effective. HTH

 

[m and m]

no i do not have a chiller but my temp is fine i have them now 8 inches off but this weekend i should be picking up two t5's with single reflectors one on each side of the MH.

 

[Brian]

2 400 watters over a 75! Wow! You could keep clams on the bottom of a tank that size with 2 - 175w MH Bulb.

 

[Carlo]

That's way overkill IMHO. Personally I've never seen the need for 400 watt halides unless your tank depth is 36" or so and you have demanding corals. A general rule of thumb I use is 150s for 24" or less. 175 double ended or 250 single ended for 24" to 30". Above 30" (rare if not custom built) it depends on the corals and the placement of them. Either 250s or 400s.

With the SUPER INTENSE light you already have why are you going to add T5s?

Not even considering the heat issues you might face down the road have you thought of how hard your coral acclimation period is going to be with that strong amount of light?

Carlo

 

[mikem]

I agree with everyone. Too much heat. I have 3 400watters on a 125gal and don't need the heat on in my house. When I open the hood, I get a sunburn. And I do use a chiller.

 

[m and m]

thanks for all the help and i have the t5's because i have 10k's on and it was pee-pee yellow lol so i added the t5's for some blue and i think it looks very nice now and now i have it 8 inches above water do you think i should make it more or is 8 good and for acclamation i have a tinted glass that goes over that side of the tank and more help will be appreciated