My alkalinity drops by about 1 dKH a day (65g mixed reef, bi-weekly 10% water changes with Instant Ocean, lots of coralline, incl. back and side walls completely covered). This happens whether I dose or not!
I used the BRSTV method of stopping any dosing, measuring alk on day 1 (8 dKH), and measuring it again on day 2 at the same time with a Hanna checker, showing 7 dKH. So I dosed back to 8 dKH and measured again after 24 hours, showing 6.7 dKH. I did it a third time showing a similar result.
I determined a daily dose of liquid soda ash of 60 ml was needed, using the BRS calculator. After dosing back to 8 dKH I set the dose to 60 ml in 12 daily 5 ml increments using a dosing pump. I checked that the pump works and it dispenses 5 ml each time. I do not see precipitation during dosing.
Today I measured at the same hour and the alk is at 7.2! I used Hanna reagent from the same bottle for all measurements.
FYI: I stopped dosing Ca during this period, as I wanted to focus on alk. It did drop from about 420 to 360.
I have not changed anything in my tank in months.
Any ideas?
I used the BRSTV method of stopping any dosing, measuring alk on day 1 (8 dKH), and measuring it again on day 2 at the same time with a Hanna checker, showing 7 dKH. So I dosed back to 8 dKH and measured again after 24 hours, showing 6.7 dKH. I did it a third time showing a similar result.
I determined a daily dose of liquid soda ash of 60 ml was needed, using the BRS calculator. After dosing back to 8 dKH I set the dose to 60 ml in 12 daily 5 ml increments using a dosing pump. I checked that the pump works and it dispenses 5 ml each time. I do not see precipitation during dosing.
Today I measured at the same hour and the alk is at 7.2! I used Hanna reagent from the same bottle for all measurements.
FYI: I stopped dosing Ca during this period, as I wanted to focus on alk. It did drop from about 420 to 360.
I have not changed anything in my tank in months.
Any ideas?