# Api vs Salifert Calcium test



## coldmantis (Apr 5, 2010)

Man chasing numbers in 2 part dosing is making me frustrated. my numbers are all out of whack since I started dosing. Right now I'm trying to determine which reading I should believe. I tested a saltwater mix I keep in storage for my monthly WC. I'm using Reef Crystals and they are known to test high in Calcium.

API Calcium - 460
Salifert - 375

I done the test multiple times with the same results, both kits are not expired. However the Salifert I did not buy I got it from a member who is leaving the hobby. The reason I'm concerned about my numbers is that I started dosing 2 part on April 1st. I also started dosing 1100ml of mag spread out 5 days to raise my mag levels since it was at 1140.

45g display + 30g long sump = around 65g total system volume, WC once a month 8g only. Tank is about 3+ years old and 8g WC is all I been doing for the pass 3+ years. I have Kalk in my ATO for about a year now.

Numbers before 2 part dosing

March 31st 2018

PH 8.3 (Ph pen)
ALK - 7 (api)
Cal - 380 (api)
Mag - 1140 (api)

April 1st 2018 after 8 gallon water change before starting 2 part

PH 8.35 (Ph pen)
ALK - 8 (api)
Cal - 360 (api)
Mag - 1140 (api)

April 5th 2018, I started 2 part on the 1st and stopped on the 5th

PH 8.62 (Ph pen), 8.2 (api). Of course PH Pen was calibrated
ALK - 10 (api) , 10.6 (Salifert)
Cal - 460 (api), 375 (Salifert) 
Mag - 1380 (Salifert), All 1100ml of mag was finised dosing on the 5th

Because the cal and alk is so high I have stopped dosing completely. I still have kalk in my ato but thats it. I was dosing 40ml of each per day until the 5th. I'm going to let the alk and Cal drop to a safer level and start dosing again maybe this time 10-20ml of each. But which Calcium number should I trust so I can adjust? All fish and corals are fine to my eyes, I even feel that the polyp extension on my sps is more since I started dosing.


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