3 XR15 or 2 XR30?

[RGoltz]

I currently have 2 XR15 pro on my 4x2x2 tank. This has been fine to get the tank started and support LPS and some easy SPS. But as the tank matures I will want to step up to some more demanding SPS.

So my question is: Should I simply add a third XR15 or should I start over with two XR30? Since I will have to buy new lids if adding another XR15, but can sell my current lights if going to thr XR30, there is a marginal difference in cost.

To me the three XR15 will provide the most even coverage, with lights 10” from the edge and another in the middle.

Is there anything I should be thinking about here? What would you do and why?

 

[Wasabiroot]

BRStv has a great video you should watch on this exact subject. They do an in depth review of the best combination of the above lights for coverage and cost. I think that it is more cost effective to get 3 smaller lights rather than 2 large lights, but I'd double check.

 

[RGoltz]

BRStv has a great video you should watch on this exact subject. They do an in depth review of the best combination of the above lights for coverage and cost. I think that it is more cost effective to get 3 smaller lights rather than 2 large lights, but I'd double check.

I’ve seen a video where they show four XR15. I believe that is the video about being cost effective but then again with four lights it’s the same, so….

I seemed to remember a video with PAR tests on three XR15 it I cannot find this anymore. For some reason I remember the spacing being 10” from the outside with one light in the center.

 

[ninjamyst]

I am going with 4 xr30 for a 70 x 30 x 21 tank only because of the 30in wide. If it's standard 24" wide, I would have went with 4 xr15.

 

[Jeff Jarry reef]

I currently have 2 XR15 pro on my 4x2x2 tank. This has been fine to get the tank started and support LPS and some easy SPS. But as the tank matures I will want to step up to some more demanding SPS.

So my question is: Should I simply add a third XR15 or should I start over with two XR30? Since I will have to buy new lids if adding another XR15, but can sell my current lights if going to thr XR30, there is a marginal difference in cost.

To me the three XR15 will provide the most even coverage, with lights 10” from the edge and another in the middle.

Is there anything I should be thinking about here? What would you do and why?

I would definitely say 4 XR15

 

[Rams]

I currently have 2 XR15 pro on my 4x2x2 tank. This has been fine to get the tank started and support LPS and some easy SPS. But as the tank matures I will want to step up to some more demanding SPS.

So my question is: Should I simply add a third XR15 or should I start over with two XR30? Since I will have to buy new lids if adding another XR15, but can sell my current lights if going to thr XR30, there is a marginal difference in cost.

To me the three XR15 will provide the most even coverage, with lights 10” from the edge and another in the middle.

Is there anything I should be thinking about here? What would you do and why?

XR15’s way to go

 

[Flux Capacitor]

I agree 4 XR15s. I have 4 pros over my 5 foot tank, and I get great par at 90% running AB+

 

[RGoltz]

I agree 4 XR15s. I have 4 pros over my 5 foot tank, and I get great par at 90% running AB+

I just made a scale drawing and it looks like if I place the lights on-center 10” from the outside edge I will have 6.5” spacing between the lights. In other words 6.5” from the inside edge of each outer light and the edge of the center light. Coincidentally I will have 6.5” from the edge of the tank to the outside lights so even all around. That was not my intention it just works out that way.

What is the spacing between your lights and have you done any PAR measurements? It looks like PAR would be pretty high in the middle. Of course I won’t know until putting the lights up..

And since I won’t really know how high the middle PAR is, I think I need to get the third light and test PAR before ordering new custom lids!

 

[Flux Capacitor]

My lights are 5” apart, and I’m 9.5” off the water. Here is the PAR readings I took, the picture shows the corresponding number I measured with the numbers in the chart :

I took the numbers with my pumps running their schedule. Hope this helps!

 

[Jon's Reef]

I would consider going with the 2 XR30 mounted transverse.

 

[RGoltz]

My lights are 5” apart, and I’m 9.5” off the water. Here is the PAR readings I took, the picture shows the corresponding number I measured with the numbers in the chart :

I took the numbers with my pumps running their schedule. Hope this helps!

Thank you, that is more information than I expected to receive. A little peak in the middle of the tank as expected but that was true running the two lights as well.

It looks like I’ll add a third XR15. Honestly this makes things a little easier as I won’t revisit the Blue vs Pro decision (I run warm white at 20% and cool white at 30% so slightly more blue than AB+, I believe).

I will have to replace my lids, though. Maybe the hardest part is figuring out what is easiest to get past my wife. One additional light and a new lid OR two new lights. Unfortunately nobody here or anywhere else can answer that question!

 

[Flux Capacitor]

You will lose a little PAR by bring the cool white and warm white down a touch, but it shouldn’t be that much. If you run the suggested spectrum that BRS came up with in their video about the g5 XR15, these are the numbers I came up with:

 

[strawberry_reef]

I just went through this debate myself on my new build. It was obviously a little more cost effective for 3 x xr15's. However I kept searching and searching the forums/ebay/marketplace and stumbled across 2 xr30 pros (g4) for a steal and went with that direction. My friend has a 120 and 90 that are predominantly SPS, both have the 2 xr30 setups and are doing amazing.

 

[RGoltz]

I just went through this debate myself on my new build. It was obviously a little more cost effective for 3 x xr15's. However I kept searching and searching the forums/ebay/marketplace and stumbled across 2 xr30 pros (g4) for a steal and went with that direction. My friend has a 120 and 90 that are predominantly SPS, both have the 2 xr30 setups and are doing amazing.

My situation is somewhat unique in that I already have the two XR15. So I either add a third (and have a new lid made) or buy a pair of XR30 and sell my current lights.

Other than having a new lid made, my only knocks on the three XR15 is:

• At 6.5” spacing, I think the PAR in the middle will be high. However, the aquascape is 5” lower in the middle of the tank and I don’t consider this a showstopper as it gives a place for the most light-demanding corals.
• I’m running out of outlets!
• Two boxes looks cleaner than three

I don’t think that I will be lacking for PAR with either configuration.

 

[lynn.reef.nerd]

why not add an xr30 in the middle of the two 15s?

 

[alton]

I like my 3 Gen 5 XR15 Pros on my 120 2x2x4. I built a light weight wooden light rack that matches my stand. I only have two SPS, everything else is LPS. The lights are set to PH14 and 50%.

 

[strawberry_reef]

My situation is somewhat unique in that I already have the two XR15. So I either add a third (and have a new lid made) or buy a pair of XR30 and sell my current lights.

Other than having a new lid made, my only knocks on the three XR15 is:

• At 6.5” spacing, I think the PAR in the middle will be high. However, the aquascape is 5” lower in the middle of the tank and I don’t consider this a showstopper as it gives a place for the most light-demanding corals.
• I’m running out of outlets!
• Two boxes looks cleaner than three

I don’t think that I will be lacking for PAR with either configuration.

No, I totally get it man. However as you probably know, Radions hold their value quite well and I am sure you would probably not take too much of a loss if you swapped over to xr30s. But like Lynn said above me, you can always add an xr30 between the two 15's as well.

 

[RGoltz]

No, I totally get it man. However as you probably know, Radions hold their value quite well and I am sure you would probably not take too much of a loss if you swapped over to xr30s. But like Lynn said above me, you can always add an xr30 between the two 15's as well.

And maybe that’s the real rub: Do I want 60 diodes or 45. And another possibly more difficult decision is whether I would stick with the PRO or go with Blue as I run AB+ (actually a little more blue than AB+) on my PRO.