AWC and DKH question - Opinions needed

[WhatCouldGoWrong71]

I was able to set up a AWC on my smaller system (70g). I run about 8.5 DKH, I put a CARX on this tank 2 months ago and have not been great at holding my DKH with less than .5 - 1.0 swings (up then down, on the tanks own being it down). But in this SPS tank, majority of the coral are happy and growing, so I’m not Uber concerned, but I would like to perhaps find a little more stability, I’ve never used a CARX before. (I do kalk at night also). So, I change 1 gallon of water everyday. The water in my brute is 11.5 DKH. Should I find the formula to use MA to bring it down closer to my tank water, or does 1 gallon really make a difference with the difference in DKH? I’m wondering if I should do the AWC at noon, thus the coral would just uptake the added DKH? Currently, it is running in the evening.

 

[Randy Holmes-Farley Verified Community Expert]

The awc is adding 1/70 x 11.5-8.5 dKH = 0.043 dKH every day.

It is not having any undesirable impact. You just need the reactor to add 0.04 dKH less every day than you would have without the awc.

 

[Randy Holmes-Farley Verified Community Expert]

I’d personally run the awc spread over the daytime hours, if you can, since that is when alk demand peaks while the reactor adds alk 24/7.