Overkill in my opinion. I have 4 T5 over a 22 gal and it grows everything if they are placed correctly.
What size is the fixture in inches? Wattage per bulb?
The 24" has a total of 96w which IMO is not enough for sps and I don't want to be concerned with placement.
i have 4x 24w t5ho's 24" over my 29g tank and grow sps fine and have had clams before do good. i use high par bulbs though:
front to back:
Ati blue +
Ati aquablue special
Kz Fiji Purple
Ati blue +
i can grow anything, my tank is 30" wide and i only have 24" wide bulbs. i retrofit them in the canopy with icecap reflectors and end caps and i used 2x workhorse 5 ballasts, one for the blue + bulbs to just view in actinics and 1 for the center daylight bulbs.
you should have plenty if you find a 4 bulb 24" t5 fixture just be sure to get high par bulbs.
Wattage means nothing. The par is all you need to worry about besides finding the color you like. I have 4x24w bulbs on a 24" fixture. The bulbs are about 4 or 5 inches from the waterline. T5 can penetrate easily 21" so it works for me.
BTW I also have a 50 gal but that has a nova extreme pro with 6x36w T5. That thing has and will grow anything I put in it. It is really just placement. Keep your SPS higher in the tank.
I don't know my pars! Lol-if y'all have a mind, check out the ones I'm looking at. www.thatpetplace.com
Maybe y'all could also further explain to me about *pars* and what I should be looking for. Please