lighting for 120 gallon

[M42]

I have 2-250 watt iwasakis right now with 2 110 watt actinics. is this sufficient for sps corals. would there be any added benefit to adding two more actinics?

M42

[Chuck S]

I have a 120 lit with 2 400watt with 2 110watt VHO actinics. I think 250watt halides would be sufficient for most SPS corals if the lights where not more than 8 inches above the waterline. If they are placed higher you would definately need the extra punch of the 400watts.

[M42]

they are around 8 inches off the water. The sand bed is also 6.5-7 inches so the actual depth is more like 18 inches and not 24 inches. does this make a difference at all?

[Chuck S]

You should do fine with that setup. You might want to make sure any higher demanding SPS is towards the top of the reef.

[M42]

would adding another 250 in the middle be a good thing?

[M42]

this one is toward the top.

[Chuck S]

You could the only problem would be the center brace. I really think you will be fine with the 250watt lights. I personally run 400's but I grow the same SPS under VHO and PC. Now there is a vast growth difference between those two but my point was to show you 250watt is fine. /ubbthreads/images/graemlins/wink.gif

[M42]

brace is clear. I am trying to figure out what is better. I can add two more VHO because the balast will run them. Or I can add 1 more MH. The net difference is 30 watts. I understand though that the quality of the MH lighting is more penetrating. So I may opt to go with this. 2-250 watt 14000K and a Iwasaki in the center. with the 2-110 VHO. Run the VHO 12 hours, the 14K 10 hours and the 6.5K 6 hours.

M42(the orion nebula)

[Chuck S]

Ouch 14K? Do not go with those. My above comments where based on you using 6500K halide lights. You must take into account the PAR that is reaching the corals at the different levels of the aquarium. Those new 14k anf 15K lights are NADA. I would use 10K at the most unless you had an HQI ballast then you could get away with using the 20K Radiums. If you truly intend to go with 3 halides which would be overkill in a 4 foot space I would choose 2 6500k with a 20K in the middle. /ubbthreads/images/graemlins/wink.gif

I do not understand what you say you can like make all sorts of changes and all this? I am under the impression this is an existing lighting system that you are just going to add another set of VHO or a halide to? You already told me you had 2 6500K halides and your talking about using 14K and only one halide.

If you do not have the lighting system yet just save yourself the trouble and buy 400watt. If you do just add a radium 20K in the center on a HQI ballast you will like it.

[M42]

I can use a HQI ballast? Are those for double ended bulbs only? Or can I use it with the radium on a mogul? It is an existing lighting system.

M42

[Chuck S]

The HQI ballast will light a double ended bulb and also the 10K and 20K bulbs

[SueT]

I agree with Chuck here. 3 250w 65k iwasaki's over a 120g 4ft tank is overkill. My 120 has been up for over 5 years now and I have used 2 250w 65k iwaskai's and 2 96w pc actinics and my sps have all the color and growth anyone would want. I did try the 400w 65k iwasaki's for one summer and it was the worst mistake I ever made. It just browned out and stunted 99% of my sps corals. I switched back and the color came right back. I agree that if you would want to go with the 400w 20k radiums then 3 might suffice for par. Otherwise the iwasaki's are going to give you the colors you want. I am using 3 250w iwasaki's over my 180 and I can't keep stuff from growing to the water surface.

[KillBill75]

add 250 watt MH