[StirCrazy]

Originally Posted by scumchug

I see the majority of people are using 250 watt lights. Do you keep the more light demanding SPS? and how low are you able to keep them in the tank? The way I understand it is that 250w is enough light, but penetration becomes an issue. Will high light SPS (acro's) flourish at the lower depths?

I can't seem to find any concrete data on running 250 watt SE bulbs with HQI ballasts. I understand that the light output is more, but can't find anything stating just how much.

you can grow SPS in a 24" tank with 150 bulbs, it is all a factor on what you want your limiting factor to be, food, light, ect.. and yes people are growing them with T5's and they are not even close to the output of a MH, but better than PC or VHO.

Ok, 250 watt is more than enough light for a 24" or less tank, almost all 250 watt bulbs are based off of European bulbs and hence the design is for European power specs, all a M80 ballast is doing is reproducing a European output from North American power input. it is more stable, easier on the bulbs starting and actually drives the bulbs properly, not overdriven. (non of this applies to a so called 400 watt HQI, because there is no such thing)

anyways I ran this type of set up for about 6 years with no problems and increased bulb life (measured with my PAR meter, not a guess) and I was growing out frags on the bottom of my tank no problem. So to answer your question, yes they will flourish with any type of 250 watt set up.

another thing to note is reflectors are just as important as the bulb and ballast combo, My 250 watt set up was putting out more PAR than a Iwasaki 400 watt system, I attribute this to the HQI ballast running the AB bulb to proper specs, and the home made reflector I was using. look at the different reflectors out there and spend the extra 15 bucks on a good one.

be careful of electronic HQI ballasts though as most under drive the bulb. Lately there have been good ones coming out though.

Steve