Kalkwasser not raising Alk

[taulgrl]

I got a Tunze Osmolator ATO from Santa and started dosing Kalkwasser about two weeks ago. My goal is to raise my Alk from 7 to 9.

I have a 75 gallon DT w 20 gallon sump. Mostly soft coral but some LPS now and in future. Evap rate is about 3 gallons per week. I added 1/2 teaspoon of Kalk per gallon of ATO water to start slow. I’m adding Kalk in a bucket first to stir Kalk and then, after letting it sit 30 min, decant supenatent off into ATO to minimize precipitate. ATO pumps water into return section of sump

I’ve been testing my DT Alk regularly and it isnt budging. Like.. at all! My Calcium has bumped up a bit from 430 to 450. PH has remained steady at 8.2.Using Red Sea for Alk. And pH Testing. Salifert for Ca testing

As an aside there seems to be a lot of precipitate in my ATO reservoir despite mixing and decanting (see pic).

why isn’t my Alk increasing?? Should I increase the amount of Kalk I add per gallon?

 

[Randy Holmes-Farley Verified Community Expert]

You simply cannot detect an alk boost that small.

It is about 25% of saturated (before some degradation in the air) and you only add 3 gallons per week in a 75 (less than 0.5 gallon per day).

That's only adding 0.2 dKH per day max. Your ongoing demand may be that much.

I'd make the alk correction with baking soda, then use to kalkwasser to keep it stable.

 

[taulgrl]

You simply cannot detect an alk boost that small.

It is about 25% of saturated (before some degradation in the air) and you only add 3 gallons per week in a 75 (less than 0.5 gallon per day).

That's only adding 0.2 dKH per day max. Your ongoing demand may be that much.

I'd make the alk correction with baking soda, then use to kalkwasser to keep it stable.

Thank you!