Rusty that is EXACTLY the problem with them! They can't read low ionic strength solutions. And even in the range of ferts, they still seem to have problems holding a correct calibration.
stinkyattic Reviewed by stinkyattic on . New RO system raising ph Just picked up a 100 gpd ro system. Ran it for about 40 minutes first to clean it out like the instructions said, then filled up a 5 gallon bucket. Ph'd the water after and the filter raised it from the 7.3-7.5 range to 10. Is this normal? Do I just need to let it run awhile to clean it out? Rating: 5