Alkaline drops much quickly

[James-reefer2017]

I usually dose 5-7ml per day to keep Alk 8.5-8.6 consistently for a while. Yesterday suddenly dropped to 8.2, so I double the dosing by add more 5 ml in the night, Today morning I test it drops to 8.0, someone know what cause this unstableness? Other elements are stable except Salinity from 1.026 to 1.024 due to water change

 

[Randy Holmes-Farley]

I cannot judge the "unstableness" from mL of an unknown product added to an unknown volume aquarium.

How much alkalinity in dKH per day are you dosing?

 

[James-reefer2017]

I cannot judge the "unstableness" from mL of an unknown product added to an unknown volume aquarium.

How much alkalinity in dKH per day are you dosing?

Hi Randy, Tks for your reply! My tank plus sump total of 116 gal. I’m currently dosing redsea foundation B KH/Alk supplement, from the bottle info , it’s 1ml/25 gal = 0.1 dkh, so if I dose 7ml , it’s around 0.15 DKH per day in my tank, am I right?

 

[Privateye]

Honestly that isn't too bad for a stocked reef tank. My 100 gallon takes about 80ml of KH buffer (I mix my own) per day. I deliver it with a dosing pump. It's completely full of coral though.

The factors at play in reef tanks are primarily growth of stony corals and the nitrification process. Nitrification (ammonia to nitrite to nitrate) results in the loss of carbonate ions. Denitrification (if present) can restore about half of the carbonate ions lost through nitrification. So it is completely normal in any aquarium, fresh or salt, that the KH and pH decrease over time. The process is accelerated by the presence of corals though. Supplementation is to be expected in a healthy reef tank.