Stability and then…

[Mark Bradley]

For circa 4 years I’ve been able to keep my tank very stable - all of a sudden my alkalinity has started to rise. I have always kept it at around 134ppm and in the last few weeks it’s slowly risen to 151ppm. What might be causing this?

I’ve raised my calcium a little but this hasn’t caused the alk to reduce either.

 

[Randy Holmes-Farley Verified Community Expert]

For circa 4 years I’ve been able to keep my tank very stable - all of a sudden my alkalinity has started to rise. I have always kept it at around 134ppm and in the last few weeks it’s slowly risen to 151ppm. What might be causing this?

I’ve raised my calcium a little but this hasn’t caused the alk to reduce either.

Are you dosing anything? What and how much?

 

[Mark Bradley]

At the moment I’m dosing 13ml alk and 15ml calcium.

 

[Uncle99]

That’s not a huge difference, maybe testing margin of error, maybe mix concentration, maybe doser needs calibration, any of these possible?

 

[Randy Holmes-Farley Verified Community Expert]

There are lots of reasons that calcification rates change over time. If alk is rising, I’d just dose a little bit less and not agonize over the why.