Discrepancy Between New/Old Salifert Calcium Test

[mynameisnick4]

My old (not expired) Salifert calcium test kit ran out of the CA2 bottle so I bought a new kit. The new kit is reading significantly higher than the old. My first test of the tank itself read almost to the max of the kit, at 495. I thought that was possibly because I am dialing in dosing and went overboard.

Today I mixed up a batch of new water with standard Instant Ocean and the kit read the water at 485. When I have tested freshly mixed Instant Ocean before it was always around 385. I tested a second batch of stand-by water I have for the QT tank it and also read high at 485.

I got out the old test kit and used CA1 and CA3 from it and CA2 from the new one, and the fresh water read 395. Is it possible something is wrong with the new test kit?

 

[Jekyl]

Possible mixing issues with the bucket? I've heard they don't come very well shaken up sometimes

 

[mynameisnick4]

Possible mixing issues with the bucket? I've heard they don't come very well shaken up sometimes

I don't think that's case. The QT stand by water is from a previous bucket of salt, the batch for the water change today is a brand new bucket.

My last test on the tank with the old kit was 405. That night I dosed 190ml of calc per the BRS calc to bring it to 420 and then tested the following night (first test with the new kit) and got the 495 result. According to the BRS calc that would have required a 1,100ml dose to do.