Alk Precipitation Issue

Cannoy · May 3, 2022

I recently started have a precipitation issue when i try dosing more than once per day. If I dose once a day may alk stays stable, but if i try to dose two or more times my alk drops and i cant keep it up. I would keep it to one dose but my alk drop 1.5dkh a day.

christianscorals · May 3, 2022

have you double checked that your doser is calibrated?

Cannoy · May 3, 2022

nope, didn't think about that. i assumed if i told the pump to split up the dose it would split up the single dose evenly since its able to does it correctly once a day.

Reef. · May 3, 2022

Cannoy said:
nope, didn't think about that. i assumed if i told the pump to split up the dose it would split up the single dose evenly since its able to does it correctly once a day.

My doser can dose less then I set it to, if the number of doses doesn’t divide exactly into number of split doses I choose, I thought it would just add a little more on one of the doses but no it will only dose the same amount each time, even if that means it doesn’t dose the amount I have set.
No error comes up, I only noticed by accident.
I now just choose a dose amount that will divide equally.

Randy Holmes-Farley · May 3, 2022

Alk dropping does not necessarily mean precipitation. It may be increased demand by corals.

Splitting a dose will not make precipitation more likely unless it changes when you dose and some of that dose is now during a time of higher pH (when precipitation is more likely).

Cannoy · May 3, 2022

Randy Holmes-Farley said:
Alk dropping does not necessarily mean precipitation. It may be increased demand by corals.

Splitting a dose will not make precipitation more likely unless it changes when you dose and some of that dose is now during a time of higher pH (when precipitation is more likely).

I believe it is precipitation because its on the glass of the display. My tank is a 20 gallons and it takes 23ml a day to keep the alk stable if i dose once per day. After i try splitting up the dose by the next day it starts dropping and i slowly start adding to the dose each day and after about a week im up to 40ml and its still not stable. I've had the tank years and this has never been a problem, it all started a couple months ago.