Real reef rock raising ALK too fast

[InspectorGadget]

Hey everyone. I wanted to know if there is anyone who has the brand “real reef rock” in their tank that have alk issues? I had to quickly break down my 40 gallon acrylic tank due to a seam failure and move all my sps corals into my Nuvo 20 without having the tank fully setup and cycled. My LFS said he had this RRR that is fully cured. I questioned dropping any rock into my tank without a separate cure but after taking the advice of the LFS, I did (I had moved 98% of the biopure ceramic media from my 40 to the nuvo 20 also). Everything was fine for a few days but without even hooking up my GHL 2.1 or dosing anything, my alk jumped from 8.2 to 8.7 then 8.7 to 9.0. I have been doing 25% water changes every 3 days to even keep the alk at 9. Also, I have 1.0 nitrate and 0 phosphates. All the corals are browning out. Anyone have issues with alk with this rock?

 

[Randy Holmes-Farley]

Artificial rock can release high alk and pH components if it is not adequately cured before use.

I'd stop doing water changes to lower it, and when it is too high, I'd use a mineral acid (like muriatic acid), or Seachem acid buffer, added very slowly and carefully.

 

[raultsu]

Artificial rock can release high alk and pH components if it is not adequately cured before use.

I'd stop doing water changes to lower it, and when it is too high, I'd use a mineral acid (like muriatic acid), or Seachem acid buffer, added very slowly and carefully.

Do you add the seachem buffer directly to the tank?

 

[Tree]

My alk never dropped below 10 when I had RRR. I put in it the tank in January and never had to dose. Once I removed some of it, my kh started to stay at 8/8.5 where I wanted it.

 

[raultsu]

I have the same issue. Alk goes up by about .2 each day. I been using seachem buffer to slowly lower it. I rescaped my tank with new pieces of RRR back in January. Never had this issue before

 

[Chad3407]

I too have wondered why my alk never goes down. It has stayed at 9.0 for over a month. No water changes and no dosing. It’s a new setup but coraline is starting g to take off as well as all the sps frags are growing. I would assume all would have to be going down but it’s not. I added about 20lbs of real reef rock to my current 80lbs about 1.5 months ago.

 

[Randy Holmes-Farley]

I too have wondered why my alk never goes down. It has stayed at 9.0 for over a month. No water changes and no dosing. It’s a new setup but coraline is starting g to take off as well as all the sps frags are growing. I would assume all would have to be going down but it’s not. I added about 20lbs of real reef rock to my current 80lbs about 1.5 months ago.

What is the current tank alk and the salt mix you use?

Water changes can boost alk, as can top off with tap water.

 

[Chad3407]

I use io salt which I know has high alk but I got it down to 8.2 which is where I wanted to keep it. At that point I added a few pieces of real reef rock and it went up to 9.0 and has not moved in a month. I have done no water changes other than maybe adding a gallon or 2 for what was taken out for fish and coral acclimating. I also only use ro/di for top off. I bought a kalk stirrer to start using but it just sits there as alk isn’t dropping.

 

[Randy Holmes-Farley]

I use io salt which I know has high alk but I got it down to 8.2 which is where I wanted to keep it. At that point I added a few pieces of real reef rock and it went up to 9.0 and has not moved in a month. I have done no water changes other than maybe adding a gallon or 2 for what was taken out for fish and coral acclimating. I also only use ro/di for top off. I bought a kalk stirrer to start using but it just sits there as alk isn’t dropping.

Well, it sounds like its hit an OK balance, not getting too high.

 

[raultsu]

well I've finally been able to bring my alk down to 8.1. doing water changes and seachem acid buffer

 

[Randy Holmes-Farley]

well I've finally been able to bring my alk down to 8.1. doing water changes and seachem acid buffer

The Seachem acid buffer (or just sodium bisulfate from amazon) is a fine way to go, as is muriatic acid.

FWIW, the buffer may seem more innocuous, and perhaps it is in handling, but the pH lowering effect on the aquarium is the same, per unit of alk dropped, as muriatic acid.