Ali rose in stored saltwater mix

[fishnugget1]

I made saltwater a week ago. I use Tropic Marine Reef. The parameters of the water were spot on. I kept it agitated and heated to 78. Now I checked and my alk is way too high. It was 8. Now it is 9.8. Salinity is fine

Anyone know how this can happen? How do I lower alk to match my tank. Or do I throw it all out

 

[lefkonj]

Was it mixing at all during the week? How much water is it compared to the display tank?

 

[fishnugget1]

20% of tank water. It was but might have stopped. Having problem with power head mixing

 

[shwareefer]

Assuming you do normal 10% water changes the net change in alkalinity will be negligible. Maintaining a minimum level is more important than trying to have an unwavering value. My tank is around 8dkh and my salt mix (red sea) mixes at 11.5. My water changes are closer to 15% total volume and my dkh moves about +.4 only to be consumed anyway.

 

[Randy Holmes-Farley Verified Community Expert]

FWIW, alkalinity cannot ever rise in normal seawater that is fully dissolved before measuring alkalinity.

It can drop as more calcium carbonate precipitates.