Fritz RPM parameters

[AFHokie]

So I have been having some odd results with RPM and was hoping to see if anyone else has experienced this or has a suggestions on something I might be doing wrong.

Disclaimer: Fritz customer support has been awesome through this process and this is not a Fritz dig.

My first 14# bag was coming out low in Alk (6-6.5) but spot on for Ca and Mg. After swapping emails a few times and verifying my low Alk measurements at my LFS Fritz sent me a new bag for free.

My new bag arrived so I mixed some up and checked Alk. 8.5…perfect. However, when I moved on to test Ca and Mg the frustrations came back. In 3 different one-gallon batches (with a bag dump and mix after 2) my Ca is consistently coming out 300-330 and Mg around 1000.

I’m mixing with 0 TDS RO, at room temp, with a pump to circulate. Mixing to 1.026. My testing on my DT is right on so I’m confident I’m not screwing up the testing (all Salifert).

Is it really possible that I’ve gotten two bad (for different reasons) batches in a row? The QC report for the first bag came back normal from Fritz. I know there will be variance but over 100ppm low Ca and 300 Mg is way beyond acceptable and means I need to juggle additives just to be close.

 

[MPCReefer]

Same issue with me, with the exception that I use the high alk mix. But I cannot get it to mix above 7.5 alk at 1.025 sp grav. Have tried cooling the water and adding salt VERY slowly but that doesn't seem to help. QC report on latest box came back within parameters at 10.5 alk but I'm not getting anything close to that. Emailed support again but haven't heard back yet.