Help! What happened??

[hopperjl16]

My pocillopora (I think that's what it is) lost a bunch of it's little polyps on one branch yesterday, but the majority of it was still ok. I caught a scarlet hermit crab hanging around it and thought maybe she'd been munching, so I removed her. Then today the coral looks like this! What's happening? All other corals in my tank are good, though my toadstool mushroom has been upset for a bit.

 

[markalot]

Most hermit crabs don't much on corals unless they are already in trouble. Scarlets are safe.

So what are your params and are they steady? Most important params are:

KH (Alk)
Calcium

KH is probably the most critical and needs to be steady. My poci's suffer when KH gets too low.

What lighting are you using and how bright?

If this is a new tank then it could be a number of things, including the water being to clean (sterile) for corals to stay healthy. Steady params and very slow changes are what we SPS keepers have to get used too. The older a tank the more forgiving it is to mistakes, up to a certain point.

 

[Roy 9121]

Looks like some type of bacteria infection. I don't know how to treat SPS for that. @Humblefish will know.

 

[hopperjl16]

Most hermit crabs don't much on corals unless they are already in trouble. Scarlets are safe.

So what are your params and are they steady? Most important params are:

KH (Alk)
Calcium

KH is probably the most critical and needs to be steady. My poci's suffer when KH gets too low.

What lighting are you using and how bright?

If this is a new tank then it could be a number of things, including the water being to clean (sterile) for corals to stay healthy. Steady params and very slow changes are what we SPS keepers have to get used too. The older a tank the more forgiving it is to mistakes, up to a certain point.

Alk has been low at 3.0, so for a couple weeks I've been dosing Seachem's reef builder. Calcium has been around 420. The tank is about 1.5 yrs old, I've had this coral for about 6 months. I do weekly 20% water changes using RODI and instant ocean reef crystals. I have a sunset montipora who is happy. Lights are the stock ones for a biocube 29 and were replaced 7 months ago.

 

[Antics]

3.0 dkh?

 

[saltyfilmfolks]

It's possible that the wc swung the alk to hard. I had it happen with Red Sea pro.

Clip some of the live stuff and see if you can save it.

Did it have good flow where it was?

 

[hopperjl16]

It is incredibly rapidly dying. It has spread to almost the entire coral only an hour later [emoji17].

 

[saltyfilmfolks]

3.0 dkh?

Yep. Retest or get verified.

 

[hopperjl16]

3.0 dkh?

3.0 meq/L. Sorry mine reads in meq/L

 

[hopperjl16]

It supposed to be 4-6 meq/L

Ok I just rechecked the water this minute and I'm at 4.0 meq/L, so my alk should be ok.

 

[chipmunkofdoom2]

It supposed to be 4-6 meq/L

Ok I just rechecked the water this minute and I'm at 4.0 meq/L, so my alk should be ok.

4 meq/l is about as high as you want to go (around 11dKh). 6 meq/l is almost 17dKh, which is way out side of the range of normal for reef aquaria.

 

[hopperjl16]

It's possible that the wc swung the alk to hard. I had it happen with Red Sea pro.

Clip some of the live stuff and see if you can save it.

Did it have good flow where it was?

Yes it had great flow, just off center from the blast from a powerhead and it had been happy there.

 

[saltyfilmfolks]

Yes it had great flow, just off center from the blast from a powerhead and it had been happy there.

And no other weird changes in what you do? Gfo added etc or a lager than usual wc?

 

[hopperjl16]

And no other weird changes in what you do? Gfo added etc or a lager than usual wc?

I added a poly-filter 2 days ago to help me decrease phosphates (I have a gha issue - long standing, almost 6 months).

 

[saltyfilmfolks]

I added a poly-filter 2 days ago to help me decrease phosphates (I have a gha issue - long standing, almost 6 months).

Well it is type of binder like gfo. I don't recall is it needs to be rinsed first like gfo.
It shouldn't have stripped the water of po4 that fast I would think.

 

[BoomCorals]

You said the toadstool is unhappy. Leathers can give off toxins that will kill sps.

 

[markalot]

So you say Reef Builder to raise KH but you didn't mention Calcium. Both need to be balanced so any dosing to raise KH needs to be married to one that raises calcium as well.

The mistakes I see mirror many that I made. Trying to lower PO4 without knowing exactly what PO4 was can harm corals. If you had GHA odds are it was consuming most of the PO4. That said, Poly Filter doesn't move PO4 much so I'm not sure that's the issue. I suspect an Alk swing from too low to too high, which will knock out most SPS, quicker than most people think. I've been there and done that.

Use two part to modify params, measure KH, and dose equal parts two part based on KH needs.

Keep an eye on the top edge of your tank for new poci's to pop up, they rarely completely vanish, fortunately. They can reproduce via polyp bailout and show back up on tank walls, on the rocks, etc.

 

[saltyfilmfolks]

You said the toadstool is unhappy. Leathers can give off toxins that will kill sps.

Possibly. But I did have two large green toadstools in my 30 with a lot of sps.

 

[BoomCorals]

Possibly. But I did have two large green toadstools in my 30 with a lot of sps.

It's not all leathers. Or sometimes only happens when they are mad as the OP indicated.

 

[saltyfilmfolks]

It's not all leathers. Or sometimes only happens when they are mad as the OP indicated.

Agreed.

I should make the leathers are always mad joke.