I have been using Fritz's RPM Reef Salt for some time, however the last two water changes (15% / 15 gal. water changes performed on a 100 gallon mixed reef) resulted in ultra low Alk (6.4 to be exact / mixed to 1.0255 sg). I did not change any of my procedures for these two water changes. Same mixing container... brought RODI water to proper temperature of 72 degrees F before adding salt per manufacturer's recommendations & calibrated refracrometer just to make sure it was not a salinity issue.
This is not the first time I have experienced low Alk after mixing with this salt.
Frustrated, today I performed the same 15% water change using Aquaforest Reef Salt with the same mixing container, heater, pump, RODI water source, time of day, ambient temperature & poured in salt at approx. same rate, etc. and the batch came out to match manufacturer's specs of 7.8 dKH at 35ppt.
So my question is have others experienced low alk issues with Fritz's RPM...are there known documented QC issues with their salt? If not, then there must have been something I did unknowingly that caused this low Alk issue.
This is not the first time I have experienced low Alk after mixing with this salt.
Frustrated, today I performed the same 15% water change using Aquaforest Reef Salt with the same mixing container, heater, pump, RODI water source, time of day, ambient temperature & poured in salt at approx. same rate, etc. and the batch came out to match manufacturer's specs of 7.8 dKH at 35ppt.
So my question is have others experienced low alk issues with Fritz's RPM...are there known documented QC issues with their salt? If not, then there must have been something I did unknowingly that caused this low Alk issue.