Is high Alk causing this?

[Greg B.]

About 1 month ago I placed my first corals in a 40 gal breeder, some montipora ect. All have been doing great until about 3 days ago. I noticed on a birdsnest coral I had a white patch on the bottom where it's attached to the rock. Next day it's quite larger. Today it is 2x the size. Noticed my alk is around 15dkh. Not good. Could this cause a sudden change in the coral? Is this Bleaching or dying coral?

 

[Randy Holmes-Farley Verified Community Expert]

welcome to Reef2Reef!

Have you previously been tracking alkalinity?

Do you know how it got that high (assuming it is accurate)?

 

[Greg B.]

welcome to Reef2Reef!

Have you previously been tracking alkalinity?

Do you know how it got that high (assuming it

I am not sure how it got up there. I am currently using instant ocean purple bucket. The alk @ 1.025 salinity after mixed is 9.5 for me. I add about 1 gal. Of tap water ( I know, it should be RODI) every 3 days due to evaporation and 25% ( 10 gal) water changes every 3 weeks. Tap water has a alk lvl of 40ppm from the well. All nitrites and nitrates are low, no ammonia, temp is 78°f. If I were to leave the tank with no water changes, is there anything that would cause my alk to increase?

 

[Randy Holmes-Farley Verified Community Expert]

Declining nitrate can boost alk, as can top off water with alk in it (like tap water). Very slow dissolution of rock and sand also can slowly raise alk if demand is very low.

 

[Alexraptor]

Since we're talking about S. hystrix here, I'd say its most definitely a possible culprit. This species is the single most temperamentral coral I have ever tried keeping when it comes to alk stability.

In my experience, even the slightest fluctuation is enough to induce rapid tissue necrosis, and to date is the only coral I've failed to have any success with, despite repeated attempts. I've had swings of 1 dkh from 9 to 10 cause instant RTN in some individuals.

 

[Greg B.]

Since we're talking about S. hystrix here, I'd say its most definitely a possible culprit. This species is the single most temperamentral coral I have ever tried keeping when it comes to alk stability.

In my experience, even the slightest fluctuation is enough to induce rapid tissue necrosis, and to date is the only coral I've failed to have any success with, despite repeated attempts. I've had swings of 1 dkh from 9 to 10 cause instant RTN in some individuals.

Problem I am having with that is it has been thriving for the last 3 weeks

 

[Greg B.]

I hate that it was thriving and all of a sudden it is dying. What I did to try to fix this is did a 80% water change. New water is 10dkh. Moved fish to another holding tank, mixed new and changed water. All parameters are down where they should be now. I am going to keep a eye from day to day. I'll keep yall updated. Not sure if this coral will survive or not