Really confused…

My 120g tank is 5 months now and I am really confused with my params…

KH used to be 3 to 4 and my Calcium 600+. I have adjusted my KH now to 10 since a couple of weeks but my Calcium is still high, 520+. I though by adjusting the KH the Calcium will go down…

I have just tested Mg which is 1560, Salinity 1.025

Why my Calcium doesn’t go down??

 

It has gone down. From over 600 to over 520.

 

+1 on Phoenix heights

I believe the most you can reduce calcium by increasing DKH is 20ppm for every degree you raise

so if Calcium is 600 and you increase your DKH BY 6 then it could come down to 480 at very most ( 6 x 20 = 120 - thus calc could drop from 600 - 480)

but when your Mag is 1560 you have the ability to bond more ions into solution
so you dont get the full 120 ppm calcium falling out / precipitating

so in your case it dropped by 80 only

your levels are OK where they are though IMO - as long as you can maintain them at that level and that calcium does not get increased at the detriment of your DKH



Steve

 

Thank you Phoenix heights & Steve, much appriciated.

 

Here is some good info;
A Simplified Guide to the Relationship Between Calcium, Alkalinity, Magnesium and pH by Randy Holmes-Farley - Reefkeeping.com

 

My params as of today:
KH 10
Cal 400
Mg 1920
Salinity 1.025
Is everything ok?
Thank you

 

I have a couple of questions what brand test kits are you using and are you adding additives to your system? The calcium and alk look good but the mag is high it should be around 1400. If you are adding some for mag stop and let it come down itself as the corals in the system will use it up or you can do water changes to help bring it down. My personal preference on mag is 1450 in our system but it is because of all the acans we keep.

 

Personally I don't like your Mag that high. I would let it fall while maintaining your Cal at 420-480 ppm. Keep an eye on the SG, don't allow it past .026.