2x150 or 2x250?

[StrategicReef]

I am wondering what is better for a 48" tank and 20" deep.

I am considering this fixture.. does anyone have good or bad things to say about it.

http://www.marinedepot.com/ps_ViewIt...n~vendor~.html

With the T5 together it is rated at 516W. should that be enough to sustain SPS grow in this 20" deep tank? I would think 2x150W is not that much for a 4 ft tank but does the T5 help the output quite a bit?

Price is not hugely different to go 250W, but the operating cost and the chiller energy bill will be quite different.

[Scissorhand]

250W

[ChurchBoy]

250's are the way to go for sps. 150's are just right if you are going to house a varied assortment of lps, sps, & softies. So it all depends on what your stock is. Mine is primarily sps so 400w is the way to go, but most of my lps & softies really suffer.

[crazedreefer]

I agree, I highly recommend going with 400w, if you can...I have run, 150, 250, and now 400's and will never go back to anything less...

[SDguy]

Depends on the bulb/ballast, but 400W of a lower K bulb is overkill IMO on a 20" tall tank, unless you are trying to grow yellow porites on the floor Many people go with 400 so they can use some of the nice, lower PAR, 20K type bulbs...

[StrategicReef]

either wattage comes with a 10K bulb. Does the T5 on the fixture not add anything?

I have run a 14K 150W vs 250W the difference is penetration to the bottom of the tank.

[takayan]

I have 3*250W DE with 14000K(2) and 10000K(1). 150W is very dark to me with 14000K.
My tank is standard 75Gal.

[anthias_lover]

2- 250w 14k

[jeffbrig]

Originally posted by StrategicReef

With the T5 together it is rated at 516W. should that be enough to sustain SPS grow in this 20" deep tank? I would think 2x150W is not that much for a 4 ft tank but does the T5 help the output quite a bit?

Price is not hugely different to go 250W, but the operating cost and the chiller energy bill will be quite different.

Your 20" deep tank probably runs with ~18" of actual water depth. If you have a few inches of sand, you probably only have 15" of effective depth. Then, consider that your sps will probably be mounted on rocks, not laying flat on the sandbed, and it's even less than that. 2x150w + 4x54w of T5 should be more than adequate light to keep sps in a tank that size.

FWIW, I've found 4 60" T5s (2 aquablue/2 blue+, overdriven w/icecaps) to be adequate on my 250g for primary lighting. That tank is a bare bottomed 72x30x27 (deeper and larger area), and the bulbs are at least 8" off the water. I typically run 2 250w halides (in DE pendants) for 2-4 hours daily to provide extra midday punch. Most people would probably say my tank is under-lit. Still, the tank has run for periods with just the T5s with no loss of color in sps.

The key is maintaining good water clarity, and having quality reflectors to maximize efficiency. I'm a big fan of retro T5 kits and separate MH pendants so that you can choose the reflector being used. I have no idea what the ones in the pre-assembled fixtures are like.

[StrategicReef]

Thanks for your more through analysis with the T5 considered, I am expecting the water level to be at 18" at most, a rather shallow tank, The tank I am setting up is 48" x 20" wide and 20" deep (75G inside volume). With the 4x54W T5, it consumes about 500W which is comparable to just 2x250W. The 250W version consumes over 750W with the T5 which seems adequate for something like a 120G and I thought it might be overkill for my 80G.

I have run 150W and 250W in my 17" deep NANO and the SPS are about the same, but they have no problem with either. The most benefit is the clams at the bottom of the tank and still be comfortably living. But the 250 generated alot more heat and the electricity bill is more. (probably because the chiller run more often too).

The thing is I look at the LFS's display tanks with some nice SPS colors but it seems not as bright as 400W at all. I have seen other people's tank with less lights and the SPS looks great too.

Originally posted by jeffbrig
Your 20" deep tank probably runs with ~18" of actual water depth. If you have a few inches of sand, you probably only have 15" of effective depth. Then, consider that your sps will probably be mounted on rocks, not laying flat on the sandbed, and it's even less than that. 2x150w + 4x54w of T5 should be more than adequate light to keep sps in a tank that size.

FWIW, I've found 4 60" T5s (2 aquablue/2 blue+, overdriven w/icecaps) to be adequate on my 250g for primary lighting. That tank is a bare bottomed 72x30x27 (deeper and larger area), and the bulbs are at least 8" off the water. I typically run 2 250w halides (in DE pendants) for 2-4 hours daily to provide extra midday punch. Most people would probably say my tank is under-lit. Still, the tank has run for periods with just the T5s with no loss of color in sps.

The key is maintaining good water clarity, and having quality reflectors to maximize efficiency. I'm a big fan of retro T5 kits and separate MH pendants so that you can choose the reflector being used. I have no idea what the ones in the pre-assembled fixtures are like.