PC rainbow bleaching / dissolving

[Humble_Reefer]

PC rainbow acro appears to be bleaching or in some way dying. The polyps still have colour but the tissue/base is significantly faded over the last 4 hrs since the lights turned on, and the coralite appear to be dissolving or chipped.

All other acros, including recent millepora additions look fine for now.

Alk and salinity looks high, and I recently switched over from viparspectra to hydras about 2 weeks ago, but I've been using the acclimation feature.

What do I do next to minimize damage?

I immediately turned off the lights and doser, and turned the temperature down from 80 to 78. My thinking was that this would slow metabolism -- I read somewhere this is the approach for bleaching.

Advice is very much appreciated. This piece was growing so well until today

 

[Humble_Reefer]

Also, there was a halloween hermit hanging out on it lately. Not sure if they typically predate corals...

 

[Flux Capacitor]

Your phosphate drop is massive, .25 to .05 in a week is a lot. Did you do something to bring them down? There has been a lot of talk on the forums lately that phosphates are just as important as alk, and I agree with it. That swing is something I’d try to get to the bottom of.

 

[Humble_Reefer]

Your phosphate drop is massive, .25 to .05 in a week is a lot. Did you do something to bring them down? There has been a lot of talk on the forums lately that phosphates are just as important as alk, and I agree with it. That swing is something I’d try to get to the bottom of.

Yeah, that had crossed my mind too. I turned on my rowasphos reactor. Should I try to increase phosphates now, or just leave it?

 

[Flux Capacitor]

I would not do anything drastic, so probably leave it on at this point. Keep an eye on the phosphates though you don’t want them to bottom out at zero. I’d just try to stay as stable as poissible see if that PC recovers.

 

[Crustaceon]

If my eyes are correct, I’m seeing base recession (stn). If so, that’s likely due to the rapid drop in phosphates. Acros can be REALLY sensitive to that.

 

[Cory]

Magnesium seems a little low to me. What is your salinity? Is no3 zero now?

 

[Duffer]

I would definitely be leaning towards swing in phosphates..happen to me where my alk,cal, and mag was stable and my phosphates took a swing like that and next thing I know acros bleached.

 

[Humble_Reefer]

Magnesium seems a little low to me. What is your salinity? Is no3 zero now?

I may dose a little Mg. Salinity is 1.026. NO3 is 10 ppm

 

[Humble_Reefer]

I would definitely be leaning towards swing in phosphates..happen to me where my alk,cal, and mag was stable and my phosphates took a swing like that and next thing I know acros bleached.

Thanks. I think you're correct.

My local reefing friends are saying it's the high alk, and that some acro dont like it so high. The climb to 11 dkh was over 2-3 months though, and it's the PO4 that has changed drastically. But just in case I've stopped dosing for now and will test at the end of today. Seems like that's my only option as waterchanges would not help the PO4 swing situation.

I've also moved the halloween crab to a new tank.

 

[SMSREEF]

The higher your Alk is, the less tolerant the corals will be to low nutrients.
If you ran Alk of 7 or 8 that 0.05 Po4 would likely be ok (although a rapid drop would likely still cause an issue, just not quite as bad).
I would stop the rowaphos for now to make sure po4 doesn’t go any lower.

Why did you choose an alk goal of 11?
I know some people have stunning tanks with high Alk and lower Alk. I’m not sure what all the tricks are that go with the higher level though.

 

[Humble_Reefer]

The higher your Alk is, the less tolerant the corals will be to low nutrients.
If you ran Alk of 7 or 8 that 0.05 Po4 would likely be ok (although a rapid drop would likely still cause an issue, just not quite as bad).
I would stop the rowaphos for now to make sure po4 doesn’t go any lower.

Why did you choose an alk goal of 11?
I know some people have stunning tanks with high Alk and lower Alk. I’m not sure what all the tricks are that go with the higher level though.

Ok thanks for the advice. Raising the alk wasnt intentional. I saw it climbing but it wasnt a linear rise so I thought I'd wait to see if it stabalized. I was going to turn the dosing down this weekend if my tests still showed it climbing. Thought I had a bit of time befor it was "too high" but hadnt considered the nutrient factor.

 

[iamacat]

I think we are on the right path with phos. What’s the pH been trending the past week or 2?

 

[Humble_Reefer]

My pH is 7.8 according to my new pH meter that arrived today. My last one broke so I haven't been tracking for a few months.

My alk is down to 10 now, which Im worried is dropping too fast. My doser is on but I put it down from 20 ml to 14 ml... Is this reasonable or is it okay if i let the alk drop faster? I know it's the spike that are really bad.

It really does look like chunks have been taken out of it (see pic updates). And parts of it still look quite healthy and the polyps are still extended... Think the crab hypothesis is still in the running, or would high alk low PO4 also have this affect?

 

[iamacat]

Alk and pH will borrow from each other. Lou Ekus has a nice little talk from MACNA

 

[Humble_Reefer]

Alk and pH will borrow from each other. Lou Ekus has a nice little talk from MACNA

Thanks, this was really helpful, I actually might remember some of it. Never know the other reason for carbon dosing...

 

[Spkarim]

If it was looking okay before the rowaphos, maybe try turning off the reactor then wait a week or two to see if it stabilizes before doing anything else. Perhaps hold off on chasing any other numbers by dosing.

 

[Fish Dr. D]

Thanks. I think you're correct.

My local reefing friends are saying it's the high alk, and that some acro dont like it so high. The climb to 11 dkh was over 2-3 months though, and it's the PO4 that has changed drastically. But just in case I've stopped dosing for now and will test at the end of today. Seems like that's my only option as waterchanges would not help the PO4 swing situation.

I've also moved the halloween crab to a new tank.

I have Mixed reed with lots of acros and 5 Halloween Hermits and they don’t hurt any corals (55 gall. Corner Tank, so high density). I have seen them climb through coral to find hard to algae. Every animal is different tho. Best of luck!