Lowering alk

Garrett0606 · Mar 11, 2020

Hi all i hope i am putting this thread in the correct area.
i am having a problem where my rocks are leeching alkaline and calciummy calcium is perfect at 450 but my alk is to high it is at 10.8. Is there a way i can slowly get rid of this alkaline. I would like to bring it down to 8 i know the corals will eventually use it up but the rocks just keep leeching as fast as they consume it. Any hell is greatly appreciated.

Thanks,
Garrett Hole

Flippers4pups · Mar 11, 2020

I personally haven't heard rocks leaching alkalinity. What are you dosing?

Garrett0606 · Mar 11, 2020

Flippers4pups said:
I personally haven't heard rocks leaching alkalinity. What are you dosing?

Thats the thing im not dosing or doing water changes anymore. I did a test to see if it was actually the rocks. I filled a bucket with salt water tested the alk put the rock in and waited a week and tested again ad it did rise.

Garrett0606 · Mar 12, 2020

Btw i am dosing bionic magnesium since thats the knly thing getting consumed

Rmckoy · Mar 12, 2020

Are you using home made rocks ( Portland concrete , oyster shells and course salt )

if not cured properly higher alk is possible .
I bought close to 200 lbs almost 5 years ago and ended up tossing it . wasnt worth the hassle

Mikedawg · Mar 12, 2020

What is the advertised alkalinity level of the salt mix you are using?

Rmckoy · Mar 12, 2020

Garrett0606 said:
Btw i am dosing bionic magnesium since thats the knly thing getting consumed

Mag , cal and alk all work together .
what salt Mix are you using ,

Garrett0606 · Mar 13, 2020

Rmckoy said:
Mag , cal and alk all work together .
what salt Mix are you using ,

I am using tropic marin pro salt.

Garrett0606 · Mar 13, 2020

Rmckoy said:
Are you using home made rocks ( Portland concrete , oyster shells and course salt )

if not cured properly higher alk is possible .
I bought close to 200 lbs almost 5 years ago and ended up tossing it . wasnt worth the hassle

Some is man made and some is keys rock

Randy Holmes-Farley · Mar 15, 2020

Garrett0606 said:
Thats the thing im not dosing or doing water changes anymore. I did a test to see if it was actually the rocks. I filled a bucket with salt water tested the alk put the rock in and waited a week and tested again ad it did rise.

How much? Was the rock artificial? Real calcium carbonate will not boost the alk of seawater.

Randy Holmes-Farley · Mar 15, 2020

Artificial cement rock can leach alkalinity if not fully cured and rinsed for a long time.

If you do regular water changes, I'd use a low alk mix, or lower it in the new mix with muriatic acid or Seachem acid buffer.