Why does ALK float over weeks/time?

[SaracensRugby]

So trying to determine why my ALK is floating up, with no changes to the system (see attached couple weeks of trident testing. I have not changed the amount dosed per day, outside of back off an ML or two; I have not added anything to the tank such as supplements or anything that could change any parameters. Temp/Salinity/water changes all stable.

The only thing I did about a month ago was scrape a bunch of coralline off the back wall of my tank. But that was it. Could there be that big of a delay in uptake of ALK? I suspected that would hit right away, not a month later.

I know this may be an incomplete picture for some, but I am racking my brain as to what it could be.

Cheers.

 

[reefwiser]

It’s the corals in your aquariums growth rate. Corals use cal and all to grow. By removing the Coraline algae you changed the amount of uptake. That why you need to test on a regular basis. An at the same time of the day to adjust your calcium and alk. That’s why you see devices like Trident and KH director on the market

 

[Randy Holmes-Farley Verified Community Expert]

I agree the demand may just be lower, which might be from the coralline, or from some other effect.