Alk randomly rising every few months

[Bars]

It happened again, suddenly my alk went from a pretty much stable 8.3 to 9.1 in 2 weeks time. I dose ATI essentials pro, have been dosing the same amount for months without problems. This happens every few months or so. Eventually my alk drops back down if I stop dosing. My calc only ever increases (or decreseas) significantly because of testing error (resulting in dosing too much) or lack of testing.

How does this happen? It's driving me absolutely crazy. Every time stuff has been stable for a while, this happens. My doser is calibrated correctly and not clogged.

I test weekly, sometimes skipping a week, and always around the same time.

 

[Randy Holmes-Farley Verified Community Expert]

Could be dosing or testing errors.

Might be changes in tank pH due to changes in home air CO2 levels (windows open/closed, number of people in the home/cooking with gas, etc) that change calcification rates.

 

[Bars]

Could be dosing or testing errors.

Might be changes in tank pH due to changes in home air CO2 levels (windows open/closed, number of people in the home/cooking with gas, etc) that change calcification rates.

Thanks Randy. My windows were replaced last Thursday, meaning a large portion of my wall was pretty much completely open for a little over an hour. Usually my windows are completely shut or on a small crack. Could that have cause the alk spike?

 

[rmurken]

Ventilation could have an effect on your pH, but not alk. Although consumer Alk tests are basically a pH titration so can’t rule out pH swings as a source of error.

Fwiw, my tank seems to do the same thing — alk consumption is consistent for weeks or months, and then stalls for a few days or a week. I temporarily scale back or stop dosing when that happens. I don’t know what causes it, but it has always picked back up again, and my tank is no worse for the wear.

 

[Randy Holmes-Farley Verified Community Expert]

Thanks Randy. My windows were replaced last Thursday, meaning a large portion of my wall was pretty much completely open for a little over an hour. Usually my windows are completely shut or on a small crack. Could that have cause the alk spike?

That seems like it would have caused an alk decrease, if anything, unless alk dosing is tied to evaporation by ATO.

 

[Rjmul]

Old thread. Possible your old windows were drafty which the tank would enjoy. New windows (properly installed) = no more draft. Lower PH, less alk consumption.
Just an idea