Help identifying Acropora stn

[Stony-coral lover]

Hi, guys, I posted pictures sometime back about some of my Acropora slowing showing white marks on the body. Sadly I never figured out what happened to cause this and it looks like it's come back. recently one coral that looked amazing started showing these white marks on it till they eventually became connected. Can anyone tell me what this may be caused by?

I mainly use a Trident Apex with some Hanna checkers to test the tank's chemistry
Alk 8.2-7.8dkh
cal 420-450ppm
mag 1450-1500ppm
nitrate 30ppm
phosphate 0-0.003

Here's a graph of the alk as you can see there was a pretty big spike and I think this might be the cause.

 

[Macdaddynick1]

That’s doesn’t look like STN. More like bleaching to me.I think it might be too high up, and po4 is slightly high. I would drop it too .2 at least.

 

[Stony-coral lover]

That’s doesn’t look like STN. More like bleaching to me.I think it might be too high up, and po4 is slightly high. I would drop it too .2 at least.

Sorry, I forgot to update my no3 and po4 those were a bit outdated. I updated them rn

 

[Dburr1014]

Hi, guys, I posted pictures sometime back about some of my Acropora slowing showing white marks on the body. Sadly I never figured out what happened to cause this and it looks like it's come back. recently one coral that looked amazing started showing these white marks on it till they eventually became connected. Can anyone tell me what this may be caused by?

I mainly use a Trident Apex with some Hanna checkers to test the tank's chemistry
Alk 8.2-7.8dkh
cal 420-450ppm
mag 1450-1500ppm
nitrate 30ppm
phosphate 0-0.003

Here's a graph of the alk as you can see there was a pretty big spike and I think this might be the cause.

That spike is nothing. I wouldn't think it was that.
Check out my spikes, not proud but nothing effected.

 

[Stony-coral lover]

I've been testing my nutrients and I think it might be my phosphates. My Hanna phosphorus ulr tester is still picking up 0 which is weird. I'm going to try dosing neoPhos to try and get it up to 0.05 over the next week. Thanks for the input so far!

 

[Pod_01]

phosphate 0-0.003

From my experience this is a potential cause and with Alk above 7.5 can be really detrimental to acro.
Also sinking PO4 going from 0.05 to zero leads to negative response.
My suggestion would be to use Reef Roids, FM Coral Dust or TM Plus NP. They contain PO4 and also feeds the corals. Just do not over do it unless you have coral mass.
Dosing PO4 in a bottle can lead to problems later on from my experience. I always ended up with algae bloom on the rocks etc… too much fertilizer not enough coral mass. Bare rock with limited coral mass is like invitation.

Your NO3 to PO4 ratio does indicates something is off. Did you use GFO or other methods to reduce PO4?

 

[Stony-coral lover]

From my experience this is a potential cause and with Alk above 7.5 can be really detrimental to acro.
Also sinking PO4 going from 0.05 to zero leads to negative response.
My suggestion would be to use Reef Roids, FM Coral Dust or TM Plus NP. They contain PO4 and also feeds the corals. Just do not over do it unless you have coral mass.
Dosing PO4 in a bottle can lead to problems later on from my experience. I always ended up with algae bloom on the rocks etc… too much fertilizer not enough coral mass. Bare rock with limited coral mass is like invitation.

Your NO3 to PO4 ratio does indicates something is off. Did you use GFO or other methods to reduce PO4?

My only form of nutrient export is a skimmer and water changes. I've been dosing Acro power for sometime and stopped once I saw this bleaching. Do you think I should start dosing acro power again or try reef roids?

 

[matt_work27]

That looks like it is getting too much light and/or not enough nutrients. Reading 0 is pretty scary. Neophos has worked well for me, but add a very small amount at a time. Your phosphate to nitrate ratio is out of whack as well, the 30 ppm nitrates might be driving ur phosphates to 0. I have had that happen when I overdosed neonitro. A decent size water change would be might be help to bring that nitrates down.

 

[Pod_01]

Do you think I should start dosing acro power again or try reef roids?

If acro power can bump PO4 it can be a good choice. I only recommend products that I used and observed the outcome.
Some products lead to NO3 others PO4 and I have not used acro power.
Feeding fish can help as well, fish poop is good food for corals.

Just for reference in my system I use skimmer, do by-weekly water change and I use activated carbon in a bag (25 ml per 100l changed overy 4 weeks). No sock, fleece, fuge etc…

I do carbon dose (TM NP Bacto Ballance) 0.2ml per 100l mainly to feed bacteria that gets consumed by corals. The intent is not nutrient control and I seen positive effects from this.

Good luck,