High Tide Aquatics

Disappointed: Kessil Lighting Question

Dorfman

Dorfman

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I recently purchased 2 Kessil A360X for my 50 gal "rock wall" tank.The tank is 20" deep and the lights are mounted 6" above deck. I did a lot of research and this was the recommended height for most consistent coverage and I also went with the recommended width based on BRS research. I just got the club's PAR meter and began taking measurements. With my current lighting program, at max lighting mid-day with CLR channel near max, Voilet at 100% and Intensity at 100% I am only measuring between 200-300 PAR consistently across the middle to bottom of the tank. Is this normal?!?! I expected and hoped for higher as I would like to grow SPS corals in this tank along with other variants based on placement in the tank. Should I add supplemental lighting or any ideas if I am doing something wrong? Please advise. After $1.2k investment I had hoped for more. Please advise.
 
That's pretty standard I think. My kessils are set so the bottom is around 100. To get 500 on the bottom Par would have to be insanely high at the top of the tank. 200-300 should still be fine for acros in my experience, I have them in all different heights in my tank.
 
250-350 is the recommended range for SPS although some folks push them to higher PAR to get different coloration. And if you’re getting 300 in the middle, that would be a good spot for SPS.

You may even want to raise the lights a bit so you get 150 on the sand for Zoas and softies.
 
PAR is not an accurate measurement for Kessil. PUR is. Still, a 300 PAR is actually quite too high and will burn your SPS. In the shop, I run about 150-200 par for the 360X.
 
200-300 PAR at the bottom of your tank is pretty high, I don’t see why you’d need higher than that, including for SPS. With the lights mounted only 6” off the water your values in the upper tank must be really high, more than enough for any PAR-hungry coral you are planning.
 
Yup 200-300 will grow SPS with no problems at all, the only worry is if that's on the bottom what about higher up on the rocks? While SPS can absolutely soak up energy, the problem is if they come from a lower light setting, very often something like a LFS, then throwing them from lower light into higher light might shock them. So if you still have the PAR meter, find out what settings are required to get values of 200-300 in your rock work area in case you have a point of reference when adding new corals, and you can always acclimate them to higher values if you still want to grow SPS along the bottom of the tank.
 
sfsuphysics said:
Yup 200-300 will grow SPS with no problems at all, the only worry is if that's on the bottom what about higher up on the rocks? While SPS can absolutely soak up energy, the problem is if they come from a lower light setting, very often something like a LFS, then throwing them from lower light into higher light might shock them. So if you still have the PAR meter, find out what settings are required to get values of 200-300 in your rock work area in case you have a point of reference when adding new corals, and you can always acclimate them to higher values if you still want to grow SPS along the bottom of the tank.
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Mike is right about that. SPS don’t die from not getting enough light for a long time, months to years even. They’ll just won’t be as colorful. But with too much light, they’ll RTN in over couple days. That’s why I keep all new colonies under 200 par and raise that level over a period of 2-3 weeks.
 
I don’t think there is a hobbyist-level meter that can measure PUR accurately. Seneye make a PAR meter that does that but it does it through calculation from baselines PAR measurements and making some assumptions in the equation. Essentially, the calculations negates some of the wavelength data within that PAR range that doesn’t affect photosynthesis like Green (green gives PAR a false range) and Red, I think. Anyway, I know Kessil lab has crazy a spectrometer setup that measure PUR and that’s why I trust their numbers more than the numbers I get from a Apogee PAR meter. Still, a PAR measurement is a good relative reference just like conductivity measurements used in salt concentration.
 
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popper said:
Let's see a picture of your setup how high is the light from water surface?
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One thing that complicates my photon distribution is the acrylic cross-members across the top of the tank. Creating “cold spots” higher up in the tank where you would not normally experience lower PAR values. Overall I think if I map it out I will know where I can stick stuff. See pics:
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Sent from my iPhone using Tapatalk
 
Coral reefer said:
How do we measure PUR? Different meter/sensor? Conversion factor from PAR?
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I wouldn't worry too much about PUR, unless you run a lot of white LEDs which does have a huge area (greens/yellow) that corals just don't use at all. That said an LED manufacturer can absolutely "goose their numbers" for PAR by having a lot of white in there. It also mattered more back in the metal halide/T5 days as those types of lights has a much more broader spectrum.
 
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