Cant get dkh to rise

[Byrd]

Total water volume 300
Magnesium 1310
Cal 430
Dkh 7.0-7.5


Just using kalkwasser I maintain 7.0abut if I dose 5ml an hour soda ash recipe 1 I get to 7.5 in 24hrs up it to 12ml an hour and still only get 7.5. What am I doing wrong? Only have a duncan frag and some soft corals. All frag size and the duncan is struggling

 

[blaxsun]

There could be a lot of factors here, including how often you perform water changes and what the alkalinity of your salt mix is, what you're using for testing kits, etc. Corals generally like alkalinity in the 8-8.5dKH range so this could be the underlying problem.

 

[Byrd]

I understand water changing can increase alk due to salt mix having a set alk but I guess I don't understand how dosing alk can't increase alk without also water changing. Just for info I use reef crystals for my mix