Corals bleaching, zoas closing

JMartin104

New member
I'm struggling big-time with my tank lately. I had a couple monti-caps completely bleach overnight. Now I have a couple where the outside rim is bleaching (about 1/4"). My cat's paw is bleaching or dying. Looks like parts are just dying or turning white. My zoas are almost completely closed, but not all and my favia has a small white spot that doubled in size over night - it's about 1/2 the size of a pencil eraser.

I run GFO and carbon 24X7, have chaeto and a skimmer. No changes that I'm aware of. Normally do WC every two weeks, but going back to 1 week. The biggest change in the past 3 months has been switching to GFO.

Ammo, N02, N03, P04 are all zero and have been for a while.
Mg = 1600+
Ca = 460
dKH = 8-9
PH: 7.8 (Almost always)
Sg: 1.025
Lights: 1 year old
 
The Moniporas sound like what I have seen with Montipora Eating Nudibranch. Not sure about the other corals. Did you just add a new frag or something? They usually hang out under the coral during the day.
 
The Moniporas sound like what I have seen with Montipora Eating Nudibranch. Not sure about the other corals. Did you just add a new frag or something? They usually hang out under the coral during the day.

It's been about a month since adding new corals. I dip everything in CoralRx before adding to my tank.
 
What's your water temp? Also, check for stray voltage. May be a long shot, but something to consider. Any small kids in the house? If so make sure they haven't put something into the tank.

Good luck.
 
You pH is too low, needs to be 8.3. Also if your temp is too low or too high it will also cause bleaching. HTH.
 
If it goes up later in the day it may not be too, too low. Maybe just a little. If you want to raise it do it slowly, small water changes will help.
 
If it goes up later in the day it may not be too, too low. Maybe just a little. If you want to raise it do it slowly, small water changes will help.

You are correct.:) He does however mention that the pH is almost always 7.8. I'm thinking there is something the OP is using that is causing his pH to stay at that level.
 
Just checked and no stray voltage.

PH has been 7.8 for 1 year with no issues. I run lighting at night in my fuge. Now, I've had my params tested at a local fish store and they tell me they are fine.

Not sure about eggs, but I took out one frag and found a very tiny quick-moving "thing". I could not tell what it was even with a magnifying glass. It was elongated about the length of a mechanical pencil lead. I was thinking it was a pod.

Water temp ranges daily from 79-81.
 
Did this problem start when you started running GFO? Your mg is high.

I don't believe so but cannot be 100% sure. I ran a different product before but was told it would irritate my corals so I switched. (From Phosguard to BRS GFO granules).
 
A month would be about the right amount of time for monti eating nudis to get going after initial infection. But your Stylophora and zoanthids are also cranky, which suggests something else.

pH is definitely low. Mag is somewhat high but that is unlikely to be the source of the issues you describe.
 
After lights out, I looked at some of my corals and saw nothing moving. I'll keep on the path of raising my PH and see what happens.
 
When you switched to GFO, did you do it blindly? Meaning did you just go ahead and run the stuff without knowing your initial phosphate level? Stripping phosphate from the water column rapidly can upset corals....and GFO does it very very quickly.

While the pH is a bit low, I don't imagine that to be the problem, it would need to drop below 7.6 or so to really start causing problems. As for Mag, not that it's too high, but how did it get that high? Are you using an aquarium branded product, or are you dumping in some DIY concoction such as ice melt?
 
Chris27,

No. My P04 levels were hovering in the range of .03 - .13 and I was changing Phosguard every two weeks. I read some corals did not like it, although, I was not having any issues. So I switched to BRS GFO. That got my P04 down to 0 and less frequent changes. Now, when my tank was healthy, I'd have to clean the glass every other day. Now, it's once every 3-4 days. So I'm wondering if there aren't enough nutrients now. My nem has been about the size of a dime for about 7 months. Two weeks ago I started spot-feeding it and it doubled in size.

I had problems with my Mg being too low with Instant Ocean standard salt. Then I switched to IO Reef Crystals and now my Mg stay high. I do not dose anything else for Mg.
 
i just had this problem with our 90 gallon, lost a large hammer and frogspawn over night as well as some mushrooms and almost lost our very large duncan. To this day we still dont know what happened, all water params were perfect, however i did change out one bulb, but i find it highly unlikely. Our duncan and some mushrooms are in another tank pulling through and getting better everyday. Our zoos seem uneffected however were semi closed for a few days. I changed roughly 60 - 70 gallons out over a period of 3 weeks and all seems well now. I wish i knew what happened.
 
Is there a chance that some corals started a chemical warfare?How fresh is your carbon?
Can you write a complete list of your corals?
 
The Nudibranch look about the size of a grain of rice or a lot smaller and will look like fuzz. They almost don't move. If you flip the Monti over at night and bring it close to the glass (still under water, if you remove the coral the Nudibranch will just flaten out and look like a white bump) use a flashlight and look very close. They are so small you can miss them. The damage they do is a small dead patch that gets larger and larger.
 
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The Nudibranch look about the size of a grain of rice or a lot smaller and will look like fuzz. They almost don't move. If you flip the Monti over at night and bring it close to the glass (still under water, if you remove the coral the Nudibranch will just flaten out and look like a white bump) use a flashlight and look very close. They are so small you can miss them. The damage they do is a small dead patch that gets larger and larger.

The only thing I see are small pods quickly running away. I see nothing larger than a pinhead (outside of the pods). Certainly nothing resembling a grain of rice.
 
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