Par meter targets for Acropora dominated tank?

aaron186 · Oct 20, 2023

I have 3 Reefi Uno Pro 2s over a 4 ft tank (reefer 425). I have a ton of flow in the tank and I plan on going with mostly acropora and pretty much all SPS in the tank. I’ve seen a lot of conflicting things and was hoping for some clarification on how to tune my lights. I have a par meter. I saw on BRS they reccomend 250-300 for acros. If I tune the top of my rocks to 300 (half way up the tank around 12-13 inch from bottom) then my bottom rocks are out of the 250 range. I asked the guy from battle corals who I ordered my first frags from and he said he tunes his to around 400. Can someone please help clarify what I should tune my lights to for the best chance at success

Thanks so much.

jda · Oct 20, 2023

Adam from BC also uses other types of lights, like MH, where you can have more PAR without damaging corals. His panels are also up really high and the light spreads well.

BRS are not professional acropora keepers - they are salesmen. I would look for more light than 250-300 at the top for acropora, but I also only have a few LEDs (radions) and you certainly cannot use as much PAR on those as I do my MH which 1000 PAR is no issue. I would go to the SPS forum and ask. 250-300 might do OK, but more light can mean more growth since the light is the only for-sure thing that gets energy to your corals. 400 might be better.

leepink23 · Oct 20, 2023

I have 4 reefi uno pro 2 as my main lighting source for acropora. I am running 350-500 par with no issues. I have great flow, feed a lot and have been growing out acros for some time. I would use the acclimation mode when adding new coral.

KrisReef · Oct 20, 2023

I think there is a wide range of PAR that corals (SPS) can live under. Getting them to acclimate is the first challenge, and after that LED's can be slowly ramped up and let the corals decide how much baking they can stand.

"Coral By Numbers," interesting idea, thanks.

leepink23 · Oct 20, 2023

Also to add, battle corals have done great in my tank.

bradreef · Oct 20, 2023

I will echo that most SPS can handle 400+ par. You would likely want to acclimate some SPS to the top. Some lower light SPS will do well at 150-200 par. You will see growth speed up or slow down, you will see colors change. You can have SPS die from a big quick adjustment in light.

aaron186 · Oct 20, 2023

leepink23 said:
I have 4 reefi uno pro 2 as my main lighting source for acropora. I am running 350-500 par with no issues. I have great flow, feed a lot and have been growing out acros for some time. I would use the acclimation mode when adding new coral.

How long is your tank?
Are you using the SPS default program in the light?
What % and how long do you set it when you acclimate? Does that have any effect on the established frags? Do you just place the frags directly where you want or do you start them on the bottom?

Hooz · Oct 20, 2023

jda said:
Adam from BC also uses other types of lights, like MH, where you can have more PAR without damaging corals. His panels are also up really high and the light spreads well.

BRS are not professional acropora keepers - they are salesmen. I would look for more light than 250-300 at the top for acropora, but I also only have a few LEDs (radions) and you certainly cannot use as much PAR on those as I do my MH which 1000 PAR is no issue. I would go to the SPS forum and ask. 250-300 might do OK, but more light can mean more growth since the light is the only for-sure thing that gets energy to your corals. 400 might be better.

I think BRS actually said 200-350 PAR, and they based that on the readings they took from the WWC tanks. But, like everything else, it all depends. If you run higher nutrients and have higher flow, you can pretty easily get away with higher PAR. It's all a balancing act.

leepink23 · Oct 20, 2023

aaron186 said:
How long is your tank?
Are you using the SPS default program in the light?
What % and how long do you set it when you acclimate? Does that have any effect on the established frags? Do you just place the frags directly where you want or do you start them on the bottom?

6 foot tank, I have additional lights to reefi but reefi is the primary source. I have a custom schedule and will be happy to screen shot when I get home.
I do 50% acclimation over 5 days and just place them where I want them to go. The acclimation doesn’t seem to affect the main coral.