Mysterious montipora damage?

[SimplyVibing]

I’ve had this montipora for about two months now. I did a water test to rule out parameters:

Ammonia: 0ppm
Nitrate: 5ppm
Ph: 8.2
Calcium: 400 mg/L
KH: 190ish ppm
Phosphate: 0.25ppm max (probably 0, I’m using API and it *always* tests 0.25ppm no matter what)
Salinity: 1.0255
Temp: 76ish F

The damage looked like bleaching at first, but now it kinda looks like someone has nibbled on the edges. New tank inhabitants include a very small Valentini Pufferfish and a yellow long-nose butterflyfish.

Another thing to consider is that it doesn’t get a huge amount of flow, but high light.

 

[Graffiti Spot]

It looks like it’s been burned on the edges where the light is hitting it most. I would switch to a test kit other than api. Your po4 is probably way higher than .25 if you testing with api and I doubt it’s actually zero. If your using api for any other tests like nitrate it’s probably more like 30 ppm nitrates and not 5.

 

[BornHandy]

Any chance you have an urchin? I recently had similar damage on a coral, then another, and another. Caught him red handed munching my pipe organ coral.

 

[SimplyVibing]

Any chance you have an urchin? I recently had similar damage on a coral, then another, and another. Caught him red handed munching my pipe organ coral.

I DO have an urchin! And he enjoys trying to pick up any coral in his path. I’ll keep an eye on him. Thanks!

 

[SimplyVibing]

It looks like it’s been burned on the edges where the light is hitting it most. I would switch to a test kit other than api. Your po4 is probably way higher than .25 if you testing with api and I doubt it’s actually zero. If your using api for any other tests like nitrate it’s probably more like 30 ppm nitrates and not 5.

I use API for everything. I would love to switch test kits but I’m super broke....

 

[vetteguy53081]

Looks like either urchin damage or High KH

 

[SimplyVibing]

Looks like either urchin damage or High KH

Hi! Urchin damage is possible. I was unaware KH could damage coral, mine is about 190. Is that to high?

Edit: did some digging and that’s the normal range. Not the culprit