Alkalinity rising on its own - Need help please

[jccaclimber]

If you take water out of the tank and leave it in an otherwise empty jar next to the tank, does the alk change in it?

 

[MnFish1]

If you take water out of the tank and leave it in an otherwise empty jar next to the tank, does the alk change in it?

yes - especially if not covered

 

[jccaclimber]

yes - especially if not covered

I'm saying the OP should try that. If its something odd in his change water, or somehow from the surrounding environment, it will show up in the jar too. I don't expect it to, but it seems like that would rule out a few things.

 

[MnFish1]

I'm saying the OP should try that. If its something odd in his change water, or somehow from the surrounding environment, it will show up in the jar too. I don't expect it to, but it seems like that would rule out a few things.

Firstly - any bacteria in a jar will cause changes in pH and alkalinity depending on the timeframe. If its something odd in his change water - he can test the change water and the tank water... its that simple

 

[TinyReef522]

Did you ever find the source for this? I’m having the same problem currently.

 

[Randy Holmes-Farley Verified Community Expert]

Did you ever find the source for this? I’m having the same problem currently.

Sand can slowly dissolve deeper down where the pH is lower, so if you have very little demand, this process may slowly add alk.

Falling nitrate (or dosing nitrate) also adds alkalinity, as do some reef products that do not state that it adds alk.

Tap water can also add alk if used for evaporation.