Strange monti issue (white marks)

[PranK]

Hi All,

I have a bunch of plating monti's in my tank who have good growth and pretty good colours. Every now and then though, I notice the tops of them go white. It doesn't look like the tell tale bite marks of a Nudi though, nor does it look like necrosis or bleaching.

Generally, the monti will recover from this and will get colour back. Then, a few months down the track it happens again.

I have lots of SPS in the tank and this issue definitely appears to be monti-specific with none of the others showing anything like this.

Params are very stable and have been like this for many months;
pH 8.2
Salinity 1.026
Ca 450
Mg 1300
Alk 9
Nitrate 15ppm
Phosphate 0.08

The lights are a long way from these montis and at a guess (from last time I tested) they are getting around 180 - 200 par.

The only non reef safe fish I have is a copperband but I've never seen him nip at any corals at all.

My tank has lots of brittle stars, bristle worms and asterinas but I've never seen these chowing down on a coral and the nature of the whitening being a periodic issue makes me think that its not any tank inhabitants.

Any ideas?

Thanks in advance.

 

[PranK]

Its worth noting that in the second pic what you see in the middle is actually not the monti. It has grown like a doughnut and not covered that section.

 

[homer1475]

My giant red monti(like yours) did this for a while. I never did figure it out, but it always seemed to happen when my nutrients bottomed out, or were too high.

Now that my current tank is stable(been a couple years now), this does not happen at all. Of course I took out the giant plate, and only have a small section growing up the back glass now.

Picture before I removed it all:

 

[PranK]

Hmmm, nutrients would kind of make sense, they are likely to be the most unstable of the tank I guess. I've been feeding a lot lately. I am actually picking up a new Nitrate test kit tomorrow so I'll see what its at (The red sea one isn't great).

 

[PranK]

And your monti looks fantastic!

 

[homer1475]

FWIW....

That plate grew so big, when I removed it, it filled a 5 gallon bucket.

Just be careful how it grows.

 

[homer1475]

This is after a disaster that broke the top plate off. I found so may things living within the folds of it, I was almost sad to see it go. But it did have to go as it was getting to big and starting to shade ither corals.

Thats about the size of a dinner plate. When they are happy, you can almost watch them add new skeleton they grow so quick.

 

[PranK]

That looks awesome! How long did it take to get that size?

 

[homer1475]

Once my reef became stable, about a year.

I started out with a frag the size of a thumbnail. They literally add new skeleton so quickly, you can almost watch them grow.

I could break a fist sized piece off, and within a week it was almost back. This was close to the glass, so I was breaking a fist sized chunk off nearly weekly.

 

[PranK]

Anybody? Could this be too much light?

 

[PranK]

For those interested, I dropped both the intensity and photo period of my lights. I've been suspicious of them causing corals to be unhappy for a while. Since doing it, the colour has started returning on these montis (which is not unsurprising, the colourless issue has been ongoing for a long time and has always resolved itself) but I've noticed a lot of positive response in my upper level SPS colonies. Extra polyp extension so far and I'm hoping for more colour too.

So, the big question now is will we see the colourless issue return with less lighting?

 

[PranK]

So, I've been watching and studying and taking notes and it appears that these white marks are caused by vermitid snails. The White is where the goo from the snail lands.

I thought that vermitid snails didn't actually harm anything but Ania from Gallery Aquatica does say they cause harm.

 

[Rick5]

I recall some folks suggesting low magnesium caused montipora to lose color or become grey. I don’t know if that’s what’s at play here, but thought I’d mention it.

You can try bumble bee snails and coral snow for the vermetid snails. I’d start by crushing the vermetid snails to see if that resolves the issue.

 

[homer1475]

Verms could most certainly be the issue here.

I have a sunset monti(encrusting type not plating type) that would never spread out(encrust), but had quite a few verms in it's way. Once I crushed the verms, it has spread out quite nicely. I think what was happening is that the coral was putting all it's strength into growing up the verms spires(the verms can outpace the monti in growing their tubes), instead of encrusting out.

Or as @Rick5 mentioned low mag. I have seen those white marking when my mag was out of line.

I do not see any verms in the immediate vicinity of that monti though, so I doubt it's a verm issue.

 

[PranK]

Here's a pic I meant to attach to my last post. I liked a vermitid right next to this Monti and there's now one coming through the Monti.

Mag is 1300 so that's ok.

I have removed and crushed a lot of worms but they do keep coming through the middle of my sps.

 

[PranK]

The pic doesnt show the verm, it is a tiny black tube right in the middle.

 

[PranK]

Here we go. Little *******.