Light settings for a 120 gallon?

[reefslugs]

I just purchased two XR30 blues. Hopefully the XR30's are not over kill for this size tank. I have them on the RMS's. I have a Plant Reef 120 gallon 48x24x24. I'd like to have a mixed reef of SPS top, LPS middle, and softies at the bottom. If that is possible. Can you recommend a starting point for the settings I should be running?

 

[RGoltz]

I don’t think the XR30 is overkill for this tank size. I am currently using 2 XR15 Pro on the same tank size and will probably add a third not because I cannot produce enough PAR with the XR15 but because I would like less shadowing (although the G5 seems to distribute well).

I would recommend spending the $80 to “rent” a PAR meter from BRS. I think you will be surprised at the low point intensity required by the XR30. I bet you run around 30%. This is fine IMO as you were also paying the premium for the G5 to provide coverage.

When you are sitting up with a PAR meter also consider that the lights - if you are looking for even light - should be toward the outside of the tank so that they are not overlapping too much light in the middle. You will also see pretty even PAR toward the bottom of the tank. So you will need to plan some overhangs or other method if you want to keep any corals that want lower PAR.