SPS and T5HO VS MH

[fencer]

I was told on a tank with 18in depth you need 6 -8 T5 HO's.

[fkshiu]

I'd get at least 6 T5HOs for an 18" deep tank if you want SPS.

The difficulty with general statements such as "can you do SPS with T5HO" is that there's a lot of variability with T5HOs. Maximizing PAR output would include:
- using individual gull-wing reflectors like Icecap SLRs
- overdriving them with, for example, Icecap 660 ballasts
- actively cooling them with fans

You won't get the same type of output with a standard Tek or Nova Extreme unit.

There's also bulb selection. With MH you've only got one bulb and one PAR reading coming out of that bulb. With a T5 unit you've got a myriad of options for bulb combos which can cause a lot of variability in PAR output.

As proven by numerous T5-lit tanks out there the short answer is "Yes" to the question, but don't expect your Oregon Tort to stay deep purple if all you've got is a two bulb Hagen Glo unit.

[Stones]

With your 4 bulb T5HO fixture, you shouldn't have any problems keeping SPS corals in the top 1/3 of your aquarium. Any lower than that, you are going to need to get a 6 bulb fixture to help increase PAR levels.

I have a SPS only 90 gallon tank and decided to switch from metal halides to T5's last Christmas. After 7 months of running the T5's, I couldn't be happier. I replaced a 2 x 250 watt HQI metal halide setup (which I had used for the past 4 years) with a 8 x 54 watt T5 fixture that does not overdrive the bulbs. Colours are improving in my acros weekly and I don't have problems growing acros on the sandbed at a depth of 24".

Like the others have said though, good individual reflectors and active cooling really help boost the PAR output of T5 fixtures so that you can keep corals you would normally need metal halide for.

[RuGlu6]

I have 6 bulb TEK T5, tank is 24" tall, and sps grows ok wth nice color at 20 inch deep

[Myka]

The way I see it is that SPS frags are cheap, why not give it a try. If all else fails you can give them away.

[subman]

Originally Posted by Myka

The way I see it is that SPS frags are cheap, why not give it a try. If all else fails you can give them away.

+1 and there are many different types of sps some will do better than others just like lps or softies. There are no hard and fast rules when it comes to lights just give it a shot.

[Canuckgod420]

I just recently swaped out my 2x250W MH system for an 8 bulb 4' T5 fixture, and I think its great(i'm only using 7 bulbs though....damn bowfront...lol).
When I stopped using ZEO my ENTIRE system had a major brown out(almost all SPS and 1 large duncan colony), so I thought this would be a great time to re-do the whole setup. Out came the halides....in went the T5's, also removed 80 pounds of rock. built new rock towers put in brown frags from mother colonies, and 3 weeks later i'm starting to get color.
Weird thing is, corals that where once green are now starting to show signs of orange and yellow with green polyps....pretty cool actually.
So to make long story short, I like the T5's for SPS.