Refugium lighting = 450 PAR

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SteveG_inDC

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I just tested the PAR in my refugium and got pretty high numbers, so I am wondering if it's the reason that chaeto is not growing -- too much light?

The fuge is lit with a used Kessil H350.
It registers over 450 par at the surface and 300+ over most of center of the water column
Light hangs about 11" over the water and the water is about 11" deep.
It's an old light, no dimmer. I don't want to raise it higher or it will grow algae throughout the sump.

Is this too much light?

Nitrates are around 1-2 ppm and phosphates have bounced around between .01 and .19 depending on how much I feed and how many hours I run the reactor with phosphate remover.
I get isolated patches of algae in both the fuge (mostly GHA) and the DT (mostly what I think is bryopsis).
 
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TexanCanuck

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Before trying to diagnose your problem, could you be a little more specific what you are seeing when you say your "Chaeto is not growing"? Are you simply reacting to the rate at which the Chaeto is growing in mass? Or are you seeing it die off? If it died off, what did it physically look like?

Not trying to be nosy - but the answer would help better diagnose the problem.

Having said all that ... That does seem like an awful lot of light for such a shallow body of water. If that's the case, I'm not sure you have to change the light ... have you tried simply reducing the photo period?

Also - can you help me understand your logic for using BOTH Chaeto in a refugium at the same time as you are using a phosphate remover in your reactor? In my experience, it is usually best to use one OR the other ... not both at the same time.

When I have had problems with Chaeto not thriving it is usually because my phosphates have been too low ... which means I have been able to address the problem by proactively dosing phosphates.

Thoughts?
 
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SteveG_inDC

SteveG_inDC

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Before trying to diagnose your problem, could you be a little more specific what you are seeing when you say your "Chaeto is not growing"? Are you simply reacting to the rate at which the Chaeto is growing in mass? Or are you seeing it die off? If it died off, what did it physically look like?

Not trying to be nosy - but the answer would help better diagnose the problem.

Having said all that ... That does seem like an awful lot of light for such a shallow body of water. If that's the case, I'm not sure you have to change the light ... have you tried simply reducing the photo period?

Also - can you help me understand your logic for using BOTH Chaeto in a refugium at the same time as you are using a phosphate remover in your reactor? In my experience, it is usually best to use one OR the other ... not both at the same time.

When I have had problems with Chaeto not thriving it is usually because my phosphates have been too low ... which means I have been able to address the problem by proactively dosing phosphates.

Thoughts?

Chaeto first started falling apart, with strands coming loose and then I found smaller clumps here and there. I still have a few tufts, but they definitely do not roll and they sink into the crevices. This got me wondering if the light is too strong.

I don't feel like I need the chaeto so much any more as my nitrates and phosphates are well under control. I was using it to out-compete nuisance algaes that were growing in the display tank. That plus a cleanup crew plus nutrient control have done the trick mostly. I do have some algae in the display, but not nuisance levels. Easy enough to pull out manually. My concern is about the future.

I have been experimenting with keeping the fuge and the reactor on timers, trying to reduce the amount of time the lights and reactor are going. I started the phosguard because the fuge seemed to be helping with nitrates but not phosphates, so the two together were exporting nutrients better than either alone.

What really surprised me was the high PAR in the sump.
 

Reef-on-a-mountain

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Chaeto first started falling apart, with strands coming loose and then I found smaller clumps here and there. I still have a few tufts, but they definitely do not roll and they sink into the crevices. This got me wondering if the light is too strong.

I don't feel like I need the chaeto so much any more as my nitrates and phosphates are well under control. I was using it to out-compete nuisance algaes that were growing in the display tank. That plus a cleanup crew plus nutrient control have done the trick mostly. I do have some algae in the display, but not nuisance levels. Easy enough to pull out manually. My concern is about the future.

I have been experimenting with keeping the fuge and the reactor on timers, trying to reduce the amount of time the lights and reactor are going. I started the phosguard because the fuge seemed to be helping with nitrates but not phosphates, so the two together were exporting nutrients better than either alone.

What really surprised me was the high PAR in the sump.
Following. I am having similar issues and I think my light is way too powerful for my refugium. I have a Mars Hydro 300 watt LED on my refugium and I just read it gets over 400 PAR in the center at 18" above the water. At first, the light burned the chaeto and killed almost all of it (it turned light green and started to fall apart). I had to turn the timer back to being on for 4 hours, then 6, and now I have the LED on for about 8-9 hours and the chaeto is a little darker but not growing at all, maybe shrinking. I have raised the LED off the water as much as possible, now I am considering adding a fogged film to the light to reduce the PAR...or maybe I'll ditch this light and get a cheaper less bright one. I have a dream of filling my refugium with other more decorative macro algae but not if I burn them all to death.
 

zukihara

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