Can Carbon Dosing Negatively affect Ricordia?

[threebuoys]

Several months ago, I began carbon dosing using the guidance found in the articles identified in the stickies to this forum.
As I began scaling up the dosages, I noticed my ricordia shrank dramatically minutes after I added vinegar to the system. Initially, the ricordia recovered after several hours. Over time, the recovery became less and less.
After a couple of weeks, I discontinued the dosing in hopes that the ricordia would fully recover. Now, about 2 months have passed since the last dosing, and the ricordia have not recovered. Is this a typical side effect of carbon dosing, or should I be looking for another culprit?

Thanks in Advance

 

[Randy Holmes-Farley Verified Community Expert]

Are you tracking nitrate and phosphate? Maybe one declined too low.

How much are you dosing per day and per addition, and where in the system do you add it?

 

[threebuoys]

Are you tracking nitrate and phosphate? Maybe one declined too low.

How much are you dosing per day and per addition, and where in the system do you add it?

I got through the first two weeks of dosing and was adding 12ml per day to a 125gal tank + ~ 15gal sump. I added the dose to the sump in the return pump chamber.

Also, I had mixed Kalk with the vinegar at your suggestion to stabilze the pH which is now running at 8.1.

At the time, nitrate was about 50ppm (Salifert) and phosphate was
between .10 and .20 ppm (Hanna).

I was also using biopellets to reduce nitrates and GFO to lower phosphates.

Currently, I'm at 25 ppm nitrates and .20 phosphate. I just refreshed the GFO several days ago because phosphates had risen from .08 to .26 since the last time I had changed it. Phosphates have started dropping again, but still at .20 .

 

[Randy Holmes-Farley Verified Community Expert]

OK, I'm not seeing any reason for a negative effect from the dosing and another reasons seems a good possibility.

Are there other corals in the tank?.

 

[threebuoys]

OK, I'm not seeing any reason for a negative effect from the dosing and another reasons seems a good possibility.

Are there other corals in the tank?.

Yes, other corals. All are rather small frags up to 1 year old. (Tank is 20 months old) Until recently, the ricordia had been one of the better for growth (split twice, ready to split again), inflation and color. Several encrusting LPS are beginning to spread out now. Until recently, I've had difficulty with Zoas, but I've been suspicious of a bi-color angel in the tank.

I an disappointed in my coral growth overall, but some seem to be turning the corner towards improvement while the ricordia has gone in the opposite direction.

Hence my search for possible causes. Regular water changes, skimmer and roller-mat filtration, UV.