IIRC 7.4 is the pH of fish blood and is the ideal # (average blood pH of 7.4 for fish as per SRAC). See -
https://srac.tamu.edu/serveFactSheet/112

Here are the charts. Focus on alkalinity not pH as alkalinity buffers large ph. swings while pH changes during the day.





Last edited by ewest; 06/02/17 10:45 AM.