PH and water density/flow?

[sphelps]

If your salinity changes from daily evaporation your density will change which can effect flow. In addition if your sump level changes from evaporation the pump head pressure will change which will also alter flow. Herbie overflows are fairly sensitive and usually require an ATO to keep things stable.

Another solution would be to change the back up drain to a standard standpipe and adjust the flow so some water enters the back-up (standpipe) drain. This way if your flow increases or decreases slightly you will avoid annoying gurgling sounds. The overall noise will be slightly louder than a traditional Herbie but may be acceptable depending on your requirements.

PH will not directly effect flow.