Lowering Kessil 360x / T5 Hybrid


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Sep 7, 2018
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Working on a SPS dominated reef tank. I am running 5 - 360X and 4 - ATI b+ bulbs in an aquatic life t5 fixture. After hearing SPS really like the 250 - 350 par range I decided to slowly lower my light to roughly 8" from 11". At 11" I was getting on average 220 par at my rocks. I have lowered it down to 9" over the last couple of weeks. Even though I have lowered it 2 inches now, par really has not changed much. I believe this is due to the wide angle lens of the Kessill. That being said I can definitely tell some of the SPS frags are a little upset. Is it possible that lowering the light does not have a big effect on par but can still be more intense? I know, sounds like a stupid question but if my apogee is to be believed Par really has not changed a lot but some sps tips are lighter and coraline seems lighter than it was. I have attached a par map of my old settings at 11" high. Starting to doubt my decision to lower and target 250-350 par. I only have a few frags at this point so I knew if there were loses while upping par it would not be the end of the world. If the tank was packed I probably would not have done this. Current lighting has t5's on for 9 hours, LED's 5 hours at 80%, couple hours at 50%, couple hour ramp on the front and back.

Fish Tank Par Hybrid 80 11inch.jpg

14 foot reef

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Feb 22, 2018
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Working down slowly will be your key. I Run 9 Kessil A360we's with T-5 hybrid's at 6" off water line.
I run my kessil's 12 hours short ramp up too 70% then T-5's come on at 1 PM go off at 9pm, Kessil's ramp down to off from 9pm to 10pm off. By lowering, you will get the par you want, just take it slow. I'm at 450 12" underwater.

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