Salt mix effect on Alkalinity help needed

[KTTX]

My alkalinity is at 8-8.2 on average.

Im changing salts to one that mixes at 9.4-9.8 alkalinity.

I do 10% water change biweekly on a 50 gallon. (So 5 gallon water change)

Does anyone know how to calculate what my alkalinity will be after the 10% water change?

TIA

 

[rkpetersen]

Ideally, should be a straight weighted average (.9 x 8.1) + (.1 x 9.6) = 8.25.

 

[KTTX]

Ideally, should be a straight weighted average (.9 x 8.1) + (.1 x 9.6) = 8.25.

That's not bad if that's the case. Thanks

 

[Randy Holmes-Farley Verified Community Expert]

Correct, smallish water changes usually do not cause a big change in alk.