Brian Treadwell
Active Member
Hey Guys , just received my TDS meter and checked my water out of tap it is at 287 ppm , my RO/DI water tested at 1 ppm is this good are bad. Thanks
RO/DI water
- Thread starter Brian Treadwell
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I suggest replacing the DI resin at anything other than 0.
You didn't list the most important number though, what is your RO only TDS? Since the membrane does 90-98% of the work this number is critical. You use the tap TDS and RO TDS numbers to calculate your rejection rate or removal efficiency. For every 2% the RO rejection rate drops you cut your DI life in half so it is important to keep it at 98% or higher for the longest DI life and lowest cost per treated gallon.
It also depends on how you are testing and what you test with. Hopefully you bought an ATC temperature compensated handheld meter and you use a squeaky clean glass to capture the sample in.
You didn't list the most important number though, what is your RO only TDS? Since the membrane does 90-98% of the work this number is critical. You use the tap TDS and RO TDS numbers to calculate your rejection rate or removal efficiency. For every 2% the RO rejection rate drops you cut your DI life in half so it is important to keep it at 98% or higher for the longest DI life and lowest cost per treated gallon.
It also depends on how you are testing and what you test with. Hopefully you bought an ATC temperature compensated handheld meter and you use a squeaky clean glass to capture the sample in.
OP
OP
Brian Treadwell
Active Member
I did buy a handheld unit do not remember the brand , but I tested the RO/DI water that is in my containers for ATO and it is about a week old , and my tap water I tested was just in a plastic cup from the cuburd probably not squeaky clean , have not tested just the RO water. Thanks
Always test directly from the RO and the DI, not from the ATO storage when you are troubleshooting your RO/DI system condition. Your ATO storage will be affected by co2 in the air, dust, plastics and much more. RO/ DI water is very aggressive so attracts anything it can to get back to its natural "dirty" state. Keep the storage sealed or covered and don't stick your hands or buckets in it.
When testing make sure to triple rinse the glass and meter in RO/DI between each sample so the previous sample doesn't interfere with the next sample and rinse at the end, cap the meter and turn the glass upside down so it stays clean.
When testing make sure to triple rinse the glass and meter in RO/DI between each sample so the previous sample doesn't interfere with the next sample and rinse at the end, cap the meter and turn the glass upside down so it stays clean.
