ALK suddenly started raising

[sherif]

I have a problem with ALK rising without dosing any.

For the last 2 years i have been dosing ALK to compensate for what is being consumed and keep it at 8 , but during the last period of time, i started noticing ALK rising without adding anything.

The only thing i was dosing was carbon ( nopox first then vodka )
Stopped dosing any carbon , started a water change to lower it but when I stopped the water changes I could see ALK rising up again.
what can be causing this increase in the first place ? high alk being released by the rocks ?

and what better to fix this problem ?

 

[I never finish anythi]

Relationship between nitrate and alk

Will someone please explain the relationship between nitrate levels and Alk. My Nitrate run 10-25. When I reload by biopellets the nitrates drop and I get an Alk spike which invariably my corals do not like.

www.reef2reef.com

 

[I never finish anythi]

http://reefkeeping.com/issues/2004-12/rhf/index.htm

 

[Reefahholic]

When Alk rises it’s never a good thing. Tank is unstable from the water change or carbon dosing.

 

[sherif]

http://reefkeeping.com/issues/2004-12/rhf/index.htm

Thanks for sharing this.However, what i'm seeing in my tank is different. The article is mentioning that stable nitrate should should not have any effect on Alk ( from the nitrogen cycle point of view ).
I have stable nitrate ( despite being hight ) around 50 but the nitrogen cycle ( increase/decrease) is not the reason for my problem.
I stopped any carbon dosing for around 2 month now , doing continuous water changes to bring the ALK down which is working , but once i stop this it is rising again ( with stable nitrate ).
I have tested my RO water and it reads 0 Alk

My current parameters :
Ca :400
Mag 1350
KH 16
@Randy Holmes-Farley would appreciate if you can comment and highlight what could be the reason.

 

[Randy Holmes-Farley Verified Community Expert]

Are you monitoring the new salt water?

How much alk demand did you previously see?
Slow dissolution of rock and sand will add small amount of alk and calcium over time.

Are you dosing anything at all?

 

[sherif]

Are you monitoring the new salt water?

How much alk demand did you previously see?
Slow dissolution of rock and sand will add small amount of alk and calcium over time.

Are you dosing anything at all?

Thanks Randy.
For the new salt , KH is 8 and it is working to reduce the kh till i stop doing the changes . it looks like kh is increasing by 0.3 in 3 days when i'm not doing any water change.

Currently i'm not dosing anything except red sea trace elements

can the ceramic sump media be adding to that ? or is it only the rocks and sand dissolution ?

 

[Randy Holmes-Farley Verified Community Expert]

Thanks Randy.
For the new salt , KH is 8 and it is working to reduce the kh till i stop doing the changes . it looks like kh is increasing by 0.3 in 3 days when i'm not doing any water change.

Currently i'm not dosing anything except red sea trace elements

can the ceramic sump media be adding to that ? or is it only the rocks and sand dissolution ?

If the issue continues, choices are a lower alk salt mix, lowering the alk in your current mix, or VERY slowly adding sodium bisulfate or other acid to the tank each day to limit the alk rise.

I doubt it has anything to do with the ceramic media.

 

[sherif]

Thanks Randy , will try that.
But in this case there is nothing i can do to stop this but only to limit its effect, correct ?
And this is probably is caused by rocks/sand dissolution ( despite that i don't see any increase in CAL as well ?

 

[Randy Holmes-Farley Verified Community Expert]

Thanks Randy , will try that.
But in this case there is nothing i can do to stop this but only to limit its effect, correct ?
And this is probably is caused by rocks/sand dissolution ( despite that i don't see any increase in CAL as well ?

A deep cleaning of the sand might stop it, if that is the source, but I'm not sure that is desirable.

The calcium changes would be fairly small.