Runaway CA, so confused

[Brisc0]

Okay, over the last three days my CA has started climbing with no supplimention, and my dKH seems to be going down a little too quickly. Im really confused. My CA is currently 480ppm and my dKH is 9.6 I have been using seachem reef buffer and alk buffer to push myself back into ionic balance over the last week, however all those products are supposed to increase dKH without impacting CA. I just did a 10% water change this morning and the readings above are current after the change. Anyone have some ideas of whats going on?
I think this kind of plays into a post I made earlier in the week about a need to buffer my top off water to the appropriate PH. I am currently adding plain RO/DI for top off, I think that buffering the top off water will help stablalize the dKH as it is also buffered in the PH buffer. Anyhow im just confused.... LoL

 

[steve-s]

Test the magnesium in the water. That is the primary componenet that keep alk and Ca in solution. If low (below 1200 ppm), just predissolve 1 tablespoon epsom salts per actual 50 gal of tank water and add several hours after any buffer addition. Keep doing this until it stabalizes and the alk stops falling. As always be sure to test before each addition. Mg should be 3x the Ca level for a proper balance.

Cheers
Steve

 

[Brisc0]

Alright, got the MG test and my MG is at 1500, so im pretty dead on 3:1 MG:CA. I am still noticing the same issues though, my CA stay high, however my ALK depletes itself if not buffered regularly. My PH also got down around 7.75 this morning and I had to use some Reef Buffer to get it back up. I will continue to buffer over the next few days to get it back to 8.2-8.4. I took Steves advice and made up a gallon of Kalk to drip tomorrow, so I will have more observations then. Mainly wanted to update on the MG today.