Are two Kessils at 50% equivalent to 1 fixture at 100%?

[Nopy117]

I’m looking into adding sps corals to my 13.5 evo. So far I have a single Kessil 160WE mounted in the center. I’m wondering if I will have more success with Sps if I add a second for more a diffused light source. However my current PAR is working very well for my coral so I didn’t want to suddenly double it.

 

[MNFish]

How high do you have the current one mounted?
I think 1 would be plenty for an EVO as they say up to 24 inch coverage and the evo is 22.
The tricky part is if you had 2 then you would probably want to mount them closer to the water as you would need less spread however if you moved them closer to the water then you would need less intensity to have the same PAR value...

 

[Jekyl]

I would look up par readings for that light. I'm not sure it will be enough for sps

 

[Nopy117]

I’m not necessarily looking to do crazy high light tenuis acro, more looking for monti and poiclipora/stylo. Maybe some Anacroporas too. If ones not enough then 2 would certainly do the trick. @Jekyl

 

[Nopy117]

How high do you have the current one mounted?
I think 1 would be plenty for an EVO as they say up to 24 inch coverage and the evo is 22.
The tricky part is if you had 2 then you would probably want to mount them closer to the water as you would need less spread however if you moved them closer to the water then you would need less intensity to have the same PAR value...

About 6” from the water surface, I run it at 100%. I’m more worried about the shadowing than I am worried about the PAR intensity. It seems a single point light would just lead to the bottom of a branching colony just dieing off?

 

[TerraFerma]

 

[minus9]

I think you'll be fine with the Kessil. I was using a single 160 for my clams in my sump while I was dealing with pyramid snails. I had it closer than I would normally have it because of the clearance in my sump and there was more than enough par to keep my clams happy. I think if you were going to go heavy sps, then a second light would be necessary to mitigate shading. I actually was using an a80 over my clams when I had them in a shallow elevated container to ensure no pyramids could make it into the container and I could see new growth on my clams all the time. If you didn't want to add another 160, then you could probably use the small reefbrites to fill in the shaded areas.
Regardless, use a par meter and map your tank in its current lighting scheme, then you'll have a better understanding of where the low light areas reside.