What are thoughts on 300 watts of metal halide on a 20 tall?

[FroggyFeet]

So I am rocking two JBJ Vipers on a twenty tall (14k 10k). Does anyone think this is to much. (sps, clams) (9 hours a day)

[pledosophy]

To much IME. One 150 HQI is fine in my 20g. Grows SPS and clams.

[LNell]

I would say that since it's a 20 tall that you don't need it because you should probably get enough coverage with just one. I say to try it with just one and see what you think. If you decide to keep both, you will probably need a really powerful fan to keep the heat from becoming a problem. I have a panaflo fan on my canopy (250w over a 15g) and it works great. I have it at full blast when my lights are on and temp has gone from 86 without it to about 76 if I want it that low. Word of warning though: the panaflo fan, especially at full blast, is pretty loud. I have it in my living room that's pretty loud all the time so I don't notice it. If you have it in your bedroom, you might want to look at something quieter. Anyway, good luck.

[30mini]

Way too much! I'm only running (1) 150W 20K over a 30 gal tank... trust me, it's more than enough to keep SPS and Clams, and the light penetration is great! I have no trouble keeping even the highest light demanding SPS!

[glassbox-design]

you could do it, but the growth and coloring would not be improved that much. honestly, it would just be a waste of electricty. s

ave the cash, and get a 150 mh set up with better reflectors...you'll get much better growth and coloration and probably equal par than 2 vipers.

jmo.

[InLimbo87]

You'd be better off (as others have said) selling both and getting a higher quality metal halide fixture. You don't need more than one pendant on a tank that long, having two is just a waste.

[roxy25]

I just have 175watts on my 20 standard

[FroggyFeet]

What would some better pendants be?