Alk constantly rising for unknown reason

[Wernerdin]

Hello!

I've been having this problem with alkalinity for almost, probably the entire time since the tank was set up, which was around 1,5 year ago. I don't dose anything in this tank.

I've already replaced all of my rocks with different ones since that was a possibility that it was leaching from those but it didn't work.
I siphoned out about 60-70% of the sand since I had a lot of it and it could have been the cause but it's still rising. I'm thinking about removing all of it because I can't think of anything else
Anyone have ideas about what could be the cause?

 

[Randy Holmes-Farley Verified Community Expert]

Slow dissolution of calcium carbonate in sand and rock pores adds alk. Most tanks have enough demand that it goes unnoticed.

How fast does it rise?

You can reduce alk in new salt water for water changes, or very, very carefully and slowly add an acid to the tank to lower alk.

 

[Wernerdin]

It rises pretty quick, approx. 1 dKH in a week.

 

[Randy Holmes-Farley Verified Community Expert]

It rises pretty quick, approx. 1 dKH in a week.

Do you normally do water change? If so, you can drop the alk to very low levels in it to offset the slow rise.

 

[Bugenar]

Get a pipe organ, they are pigs for alk and will quicky neutralize it for you. Also cats paw stylophoras are good, any acro or birdnest as well.

 

[Wernerdin]

Do you normally do water change? If so, you can drop the alk to very low levels in it to offset the slow rise.

Yes, I do water changes once every 2 or 3 weeks.

 

[Wernerdin]

Btw, I have one lps, soft corals and anemones.

 

[Wernerdin]

What if I remove all the sand? Would that help?

 

[Randy Holmes-Farley Verified Community Expert]

What if I remove all the sand? Would that help?

Probably,,but that’s not the approach I’d take.

You are using ro/di, right?

 

[Randy Holmes-Farley Verified Community Expert]

If you are not doing regular daily water changes by awc, then one option is to add a tiny bit of alk reducing acid each afternoon (when pH is highest).

This is a recipe:

https://www.reef2reef.com/threads/s...in-new-salt-water-or-in-display-tanks.362825/

 

[14 foot reef]

What test kit are you using ?

What salt are you using for your water changes ?

 

[Wernerdin]

What test kit are you using ?

What salt are you using for your water changes ?

I'm using salifert test kit and aquaforest Salt.

 

[gbroadbridge]

I'm using salifert test kit and aquaforest Salt.

Which AF Salt? The Reef salt or the Probiotic Salt?

 

[Wernerdin]

Which AF Salt? The Reef salt or the Probiotic Salt?

Reef salt

 

[14 foot reef]

Reef salt

What does the Manufacturer say that salt should mix at, I tried researching it but I cant seem to find the data.

 

[Randy Holmes-Farley Verified Community Expert]

What does the Manufacturer say that salt should mix at, I tried researching it but I cant seem to find the data.

About 8 dKH at 35 ppt:

https://aquaforest.eu/en/products/seawater/marine-salts/reef-salt/