Always good to know. Thanks. I just keep checking my R/O water, it's at 0ppm's. When that changes I recalibrate.
LOC NAR on probation Reviewed by LOC NAR on probation on . PPM Calibration Solution - DIY I just wanted to pass on some information I found. Probably obvious to most but it could save some money. No need to purchase calibration solution. 1mg of solute per 1L of water would equal 1ppm. So to get a 2Kppm solution would need to put 2g of salt into 1L of purified water.. or just put 1g of salt into .5L of purified water. The water MUST be purified, pure water has almost no conductivity, compared to tap water which has all sorts of contamination (tapwater here reads about 80ppm). So Rating: 5