stick w/ 250w or switch to 400w mh?

[glennr1978]

I already asked this question in the aquaculture forum but got no response there. I have a 6'x3'x1' frag tank that is currently lit by a pair of 250w radiums in LME reflectors suspended about 2' above the water. Half of the tank is LPS and softies and the other half is SPS. Should I switch out the 250 on the SPS side for a 400? Or will it even make much of a difference? I want to maximize color and growth. I currently don't even use a fan and heat is not an issue. If heat becomes a problem with a 400 I can easily set up a fan. Thanks!

 

[rlpardue]

I think the difference between a 250 Radium vs a 400 Radium is negligible in your application. With 1' depth, you don't need extra punch. I ran some PAR tests with 250/400 Radiums in Galaxy ballasts with LumenBright reflectors, and going to 400w only added about 20% or so PAR. Not sure why...

 

[glennr1978]

Cool. just out of curiosity, do you recall what the #'s were? I'm also running galaxy ballasts. Currently running them on 250w HQI.

 

[rlpardue]

I wrote them down in a notebook; I"ll post them when I get home.

My ballast settings were 250HQI vs 400w normal. If you amp it up to 400w Turbo I think you'd see more of a difference, but I don't personally want to burn up 400w Radium bulbs in 6-8 months. (Many people love that method though!)

 

[glennr1978]

IIRC, 400w radiums aren't supposed to be run on the turbo setting. Marine Depot has them on sale for the same price as a 250 right now. I may go ahead and order a 400. Worst case scenario my electric bill goes up a couple of bucks a month.

 

[glennr1978]

Anyone else care to chime in? Do you guys think I would get better growth and/or coloring with a 400w?

 

[hedgedrew]

For 1 foot depth? Na.

 

[dvanacker]

If LPS and softies are doing good on the other side with the same light I would hesitate to say you are going to need more light for SPS. 3'x3' footprint is pretty big.....if you wanted even coverage with the lumenmax elite (is that 20 or 24" reflector?) you would have to raise it up pretty high. Unless you only want SPS in the middle 2ftsq.

Anyway you could stop guessing if you had a par meter but my point is SPS needs more light than softies/LPS so if that side is the exact same and those corals are doing well you will need more for the SPS.

 

[trueblackpercula]

It will not make a differance for your set up. But what will change based on my experience when I went from 250 to 400 was more heat a d higher electric bill.