175W enough for SPS?
 

Alright I'm stuck. Again :lol:

Is a 175W MH gonna be enough to have SPS?

The tank is only a 20 tall, and I'd rather not have a more powerful light than I need, since I do plan on running them for 8 hours a day. But if I get the 30 tall which has the same dimensions but longer, I might want something more powerful... any thoughts would be helpful.

Hmm I should have put this into a different spot, it should probably have gone into the equipment forum.

Yes you can grow most sps under 175 watt MH but many of them will need to be placed fairly high up to get good colour.

Iwasaki 14K (sometimes called 15K) 175 watt MH with an electronic ballast has been tested to have the most PAR of the 175 watt bulbs.

Cheers,
Vic

I used 175w for the first year of SPS keeping. They'll live, and grow a bit, but not the same as you'd get with bigger bulbs. Especially if you go deeper, you'll want at least 250w.

The 175 watt Iwasaki with an electronic ballast is supposed to have as much PAR as any 250 watt bulb according to Sanjay Joshi.

It's a pricey bulb though.

Cheers,
Vic

If you do the 20" deep tank, you could go with HOT5s, 6+ bulbs would do nicely. Just thought Id give you a bit more to think about.:biggrin:

Well, the plan is to have 2 T5HO bulbs running 12 hours a day above the tank anyhow. This was more because of colour considerations more than anything, I want to use a 10K bulb because I like the really bright white sunlight effect. I was planning on using a XM 10K bulb with a PFO electronic ballast run 8 hours a day, and and 2 actinic or 50/50, maybe a Fiji Purple T5HO on for 12...

Does this change the equation at all?

OH, and the tank is like 15 inches deep, part of the tank will have a 3" sandbed (the seagrass part)....

I used to be using 150wt MH, at a depth of 21in, and have switched to t5's. with the t5's at the same depth, i have experienced much more growth, and color in my SPS.