Lighting upgrade on 100 gal cadlights

dmcoates · Feb 17, 2016

hey guys. I have a 100 gal cadlights 48"x24"x20" and I am running 2 xr15 pro. I need more light. Right now I am having good results with the sps being on top of the rocks. About 300 par. As my sps grow and start to shade out of their corals I forsee issues. I am thinking about adding another xr15 in the middle. How does that sound?
I was also think about going with sbreeflights, but I really like the sleek look off the radions. I don't really want to spend the money to buy 2 new xr30s.

I could use some feedback.
I have attached a few pics of my tank

saltyfilmfolks · Feb 17, 2016

Hi, your dead on in your trouble shooting. coverage is as important as intensity. besides looking its better for the corals health and growth. ultimately itll be your budget choice of course.

I know a guy with some info you can use.

@mcarroll do you have those great coverage chart you made?

mcarroll · Feb 18, 2016

Even Ecotech only claims an 18" x 18" coverage area for those, so I think a third unit should be a no-brainer. Even a fourth wouldn't be too many, and you could run the fixtures a little cooler.

Here's a few rough illustrations that may or may not help visualize things. Lights in the example are mounted at 12" with 90º lenses.

Two fixtures:

Three fixtures:

Four:

You may be able to crowd four up a little bit more.

dmcoates · Feb 18, 2016

Thanks for the feedback. I am going to pick up another xr15, sounds like 3 xr15's in the 48" tank should be enough for awhile then. Thanks a lot for the feedback.

cnseekatz · Feb 18, 2016

You might want to consider upgrading to XR30s. Two would definitely give you the spread you're looking for, especially if you utilize their Wide Angle Lens options (TIR). I'm not sure how the math works out between 3 XR15s and 2 XR30s, but you'll get more light, and more flexibility with the 30s over the 15s.

mcarroll · Feb 19, 2016

I think the spread is essentially the same...a near-circle. Power is different though!

XR30w Pro
1100 maximum PAR
170 watts
$750

XR30w
900 max. PAR
150 watts
$650

XR15 Pro
875 max. PAR
75 watts
$400

You're basically back to the two-light model depicted in post #3 above....larger, more-shady areas. About like this:

True with the 30's you are in better shape for intensity since the covered areas can be >200% brighter, but not coverage.

If the PAR numbers are to be believed, you're much better off doing it with the XR15's. Four XR15 Pro are about equal to two Xr30 Pro for cost.