Too high dKH and low PH

[jeffaquarius]

I am having problem with my water parameter and still trying to find a way to put it back on the right track. I Have done 15% WC twice and have dosed PH buffer, Mg and Calcium but readings bounces back. Has anyone ever used a carbonated water (sparkling water) to lower the alkalinity level?

60 gal DT
10 gal sump
PH 7.8
Mg 1240
dKH 21
Cal 360
Sp. G. 1.026
Temp 77

 

[Holygral]

Stop dosing the PH buffer, it is what throws the Alk off. 7.8-8.2 is fine. Do water changes and it will slowly come back down, I would add a calcium supplement to help balance it out until it lowers. This will help Reef Chemistry Calculator

 

[ccCapt]

Are you sure about that alk reading? 21dKH is pretty much impossible.

 

[Daniel Fishy]

Google Advanced Aquarist cal and alk good info on balancing and maintaining them.

 

[jeffaquarius]

I repeated the dKH several times and I have consistent readings. I just did another 15% wc and I will have another readings later. I use KENT reef salt with the following parameter before pouring in.
PH 7.6
Mg 1350
dKH 15
Cal 520
Sp. G. 1.025
Tem 77

The link that Holygral sent is very useful it handy. Reef Chemistry Calculator

 

[jeffaquarius]

After another 15% wc my parameter is slowly back on track. The dKH went down to 16 then I just added calcium and magnesium. The dkH went up just 1 point. Lesson learned by not tinkering with PH if dKH is already high.