Does alk drop without corals?

[Ferrell]

Heres what I have for new DT:
75/30
Sump
Socks
Skimmer
return pump
Set up 11-21-17

Salinity 34
Ammonia 0
Nitrate 5
Calcium 420
Mag 1600 haven’t dosed
Alk 8

Used dry reef saver, dry Fiji, rodi
And hw reefer salt
Have 2 reef chromis, 2 clowns several hermits and snails.

My Alk drops .04-.05 every 3 days. Why?
Getting ready to put in euphyllia in next couple of weeks and want to get Alk up. When below 8 been using sodium bicarbonate to bring back up to 8-8.2. Will dose kalk when get Corals
Why is the Alk dropping?

 

[Undertaker]

how old is your tank?

 

[SashimiTurtle]

0.04-0.05 dKH over a few days, I'd guess normal precipitation. Calcium and carbonate will naturally bond together in the water. Magnesium slows it but doesn't prevent it.

I can't even test below 0.1dKH...

 

[SashimiTurtle]

how old is your tank?

Set up 11-21-17

 

[Randy Holmes-Farley Verified Community Expert]

Alkalinity drops for many reasons, some of which happen without corals, and your drop is very, very small. Nitrification of ammonia depletes alkalinity, as does abiotic precipitation of calcium carbonate on heaters, pumps, etc. [emoji3]

 

[Ferrell]

Thanks for the responses. This being the first reef set up I’ve been monitoring everything to get a sense of it all... that just didn’t make any.
Thanks again

Edit. My error. It drops from 8.0 to 7.5 or so every 3 days. .5 not .05. My error