Odd tissue response in acropora that occurs after some water changes.

[rbadred]

Hey all,

I have observed an odd response that one of my acros has sometimes after water changes. This only happens with this acro but doesn't happen every water change, but it did after my most recent one so I wanted to see if anyone else has seen something similar. One or 2 of the smaller coralites at the end of the branch will have a dark patch of what looks like missing tissue. This has occurred about 4 times total with this acro and is always healed by the next day. This coral has been growing very quickly and does not show any signs of stress when this occurs i.e filaments or closed polyps like you might see with burnt tips. I'm using reef crystals and all my WC water match my tank fairly closely except for Alk and normally see a .2 dkh bump in Alk after a water change so that may be the cause. I normally pause dosing AFR for a few hours after to bring it back down. I add NoePhos and NeoNitro to my WC water to match my tank because I have fairly low nutrients. Overall I'm not super worried because it has always healed within a day but I know its probably not ideal for the coral. My only theory is that after a water change those small coralites grow a bit faster causing a tear in the tissue that gets bigger because of my flow but I'm sure people on here know way more then me so id just like to know what you guys think. 2nd pic is zoomed in to what I'm referring to and 3rd pic is the day after all healed up. Also is this a slimmer? That's what it was sold to me as but has a different skeletal structure imo.Thanks!!

Parameters
Temp: 78
Salinity: 1.0253
Alk: 8.4
Nitrate: 7.2
Phosphate: .03
Calcium: ~425
Mag: ~1300

 

[Pod_01]

From the blue it is hard to tell, but the coral looks happy.
What you described is sometimes called burned tips and it happens when the Alk is elevated and PO4 is low. Your Alk is ok but the PO4 could go up a bit to 0.05 ppm minimum.

I have very similar parameters, my PO4 is at 0.1ppm.

No exposed tips yet,

Good luck,

 

[rbadred]

From the blue it is hard to tell, but the coral looks happy.
What you described is sometimes called burned tips and it happens when the Alk is elevated and PO4 is low. Your Alk is ok but the PO4 could go up a bit to 0.05 ppm minimum.

I have very similar parameters, my PO4 is at 0.1ppm.

No exposed tips yet,

Good luck,

Thanks, ya I've trying to get in up by dosing slowly but i think it's still being absorbed by my rock.

 

[Pod_01]

Thanks, ya I've trying to get in up by dosing slowly but i think it's still being absorbed by my rock.

So there is this:

It is new well at least where I am located, it acts like fish poop.

I been using it for 3 weeks or so and it has not increased PO4 but corals look happy and some of my algae has decreased.
It has PO4 that bacteria needs to break down so it doesn’t bind to the rock as much. Also the standard test kit doesn’t pick it up right away. At least that is my understanding.

Not saying it is magic but my corals have responded well to it so far:

Good luck,