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[jakeh22]

Hey guys first off I have a 90gal so I recently switched out my 6 t5s for one ap700 I noticed that my acropora is bleaching a bit after about 4 weeks. I ramp it up to 100 percent and everything seems to be doing fine but that. I acclimated them and everything. I have some acropora crabs can they be causing some flesh loss. The only thing different is I added a Kessil 360we to my fuge and now my ph is steady in 8.0. Can my blue spectrum be too strong? Have some pics to come tank is about 2 plus years strong now

more to come

 

[chipmunkofdoom2]

I would not suspect the crab, I would suspect light shock. Going from 6x T5s to one Kessil AP700 is a big change. The light spread of T5s and LEDs is really different. Depending on coral depth, 100% on the AP700 might be far too much light. What is your tank's measurements?

 

[TexasTodd]

100% is really high for LED. 4 weeks, when did you go to 100% and what were you at before that change? Most people run around 30-50%.

 

[jakeh22]

Ya 30 to 50 but one one a 90 gal with how many t5s I had prior 100 shouldn’t be so much

 

[ctpeasy]

Ya 30 to 50 but one one a 90 gal with how many t5s I had prior 100 shouldn’t be so much

If you don’t have a PAR meter, then number one suspect is too much light. LED’s are deceptively intense. I started mine on 20% and gradually moved up over time.

 

[TexasTodd]

Pretty much the only people running at 100% are aquaculture with fixtures like 24" or more above the water. Almost for sure too much light. Also depends on spectrum. Whites generally ran at 1/4-1/3 rate of blues.

 

[jakeh22]

So I had the lights since March 10th everything else is flourishing.

 

[TexasTodd]

With no changes to intensity since March 10th? If so, then that is a little weird but I've seen it take a while. Has your alk gone up or nutrients gone down? Is the flesh coming off or just getting lighter? Top or bottom of coral? Close up pics and also the crabs. Do any of the crags have hairy legs?

 

[jda]

It is almost certainly the lights. You went from a high-quality full-spectrum wide source to a so-so cut-spectrum point-source with hotspots. The Kessil is not as good of light quality as the T5s - some corals need a long time to adjust and some never do. Bleaching is not the end of the world - death and tissue loss can be.

Even if the T5 were putting out the same PAR as the LEDs, the coral need time to adjust to the spectrum differences. I would not let them get above more than 40% for a while. ...maybe raise them up 1-2% a week for a while?

Where are you losing flesh? Tips, base?

 

[jakeh22]

I’m losing it at the tips and not today I see a lot more

 

[OceanL0ver]

The fuge may be consuming too much nutrients(nitrate and phoshate) your corals may be starving.

 

[jda]

Lower N and P does not cause death. Lighter, higher contrast colors are possible, but some people like those... and some people prefer the rich, darker colors. In any case, low and N and P does not kill coral with natural methods since it cannot take them down below a low equilibrium where there is always some present to drive the equilibrium, but not too much - media can take them too low, so if you are using Organic Carbon, GFO, LC, etc. then you might be killing corals... but this is not really possible with a fuge.

 

[jakeh22]

Would it take that many weeks to bleach? Wondering if some hitchhikers may be the culprit I have some new corals that came on rock but did my normal coral rx dip

 

[jda]

Are they bleaching out to full-white, or just lighter in color?

Sure... it takes a while. If the corals were healthy under the T5s then they can use some of those reserves when you change out lights, ship or otherwise stress them.

 

[jakeh22]

Hey to add I am loosing all my Duncan’s or my torch corals anything that has flesh hard coral in short. I have been doing water changes and can’t figure it out.

 

[TexasTodd]

My guess is that this all started with the lighting change and now a Cascade of infection. I'd find out the average percentage people are successfully running that light, and height, and change to that. Its going to take a while now for things to settle.

 

[jda]

Did you put the T5s back on? You downgraded your lights. This is pretty easy to figure out. If you do put them back on, it will take as long to recover as it did to slide.