Low KH

[TonapahNorth]

My KH is dropping into the 7.2 range between 15% water changes. However, Ca stays in the 410-420 range. Mg stays about 1420. Ph seems to fluctuate but drops as low as 7.8.

I am new to this. I don't dose at all. I just do WC with SeaChem Salinity salt every 5-7 days or so. Corals and critters seem happy and maybe I'm just chasing numbers but I "think" my KH should be higher.

Can anyone tell me a solution to increasing KH without increasing Ca?

Thanks.
Tonapah

 

[jduck]

Dosing baking soda will increase alk. What is the kh of your tank after wc? What is the kh of your WC?

 

[TonapahNorth]

I'll check today and follow up. Today is WC day. I'll test WC as I've never done that.

 

[TonapahNorth]

WC water is 10.2 dKH according to Red Sea Pro kit.
Ca is 440
Mg is 1400
Ph is 8.5

Water change is 5g which is about 15%