Doubling up on Kessils, how far to decrease intensity?

[ntayler]

So I currently have 3 kessil a360 over my 150 gal (6ft long). It’s a deep tank at 29ish inches, and I’ve been debating on how to best upgrade for coverage and par increases. I just bit the bullet and bought 3 more for a total of 6 [emoji51]. I’ll have 2, 360’s over each third of the tank (separated by braces). Lights are mounted at a height of 8-9 inches over the water surface.

This is obviously a lot more light so I am wondering where I should start my intensity initially. Currently I’m running the 3 at 95% for about 10 hours (brief ramp up and down on either end for a total on time of about 12 hours).

When I add the other 3 kessils, should I decrease my intensity to 45% Or is that still too high?

And how much/often can I bump it up? Is 10% a week too fast? Should I expect algae problems with the light increase?

I have a decent amount of frags (mostly lps) that I don’t want to kill. Hoping to start getting more Sps going after the upgrade.

Thank you for any insight! R2R has been such a phenomenal resource!

 

[14 foot reef]

Have you done any par meter testing? I just went from 4 over my 92" x 36" x 26" deep reef area to a total of seven now. Mine to are 8 1/2" to 9" above water and Im still not getting the par or pur I want, and not getting close to what BRS tested. I'm thinking of dropping down to 3"-4" and retesting par. Curious to know your par readings. The attached par reading is at mid tank level about 12" under water surface. but the bottom readings at sand bed are barely hitting 75-95 on the par.

 

[jml1149]

Just curious, and not to be silly, but in a tank with no coral, how do you know you don't have enough light?

 

[saltyfilmfolks]

$15 lux meter.
Meter the intensity at the surface of the water before you add the new lights. Add the new lights and match the intensity across the top of the water.

https://www.amazon.com/dp/B00LSFR0F...t=&hvlocphy=9061183&hvtargid=pla-505585159192

You can do the same with a par mater.

 

[14 foot reef]

Just curious, and not to be silly, but in a tank with no coral, how do you know you don't have enough light?

I did testing and documentation with the same Par meter as the very scientific approach and testing BRS TV did on the Kessil 360's. I'm coming up with lower numbers they they came up with so I trying to determine if lowering would help. There seems to be some good data backing this approach, as my 360 are the Wide angle lens not the narrow. So if anyone has any other scientific ( PAR ) data on Kessil light height above water, that would be great.

 

[jda]

Which PAR meter? Some of them need a correction factor applied. I have no idea what BRS came up with, but I found Kessils very weak as well on an Apogee 510.