tds conversion question
- Thread starter jmp21677
- Start date
- Tagged users None
redfishbluefish
Stay Positive, Stay Productive
Staff member
Super Moderator
Reef Squad
Partner Member 2024
Excellence Award
Article Contributor
NJRC Member
Hospitality Award
Can't do it. THIS might help.
It should be reading as close as you can get to ppm. Depends on the meter though as some are not temperature compensated and some read electrical conductivity in microsiemens.
What is TDS? - HM Digital
http://www.tdsmeter.com/img/selectionguide.jpg
What is TDS? - HM Digital
http://www.tdsmeter.com/img/selectionguide.jpg
jmp21677
Well-Known Member
- Joined
- Aug 1, 2009
- Messages
- 672
- Reaction score
- 284
This is the bad part! I think it is reading in ppm. My tap water reads about 84ppm. Once water comes through my 5stage ro unit it reads about 350ppm? Membrane is less then a year old and all but one filter was changed in the last two months?
What is your tap water TDS, RO only TDS before the DI and final RO/DI TDS?
Use a squeaky clean clear glass drinking water glass, washed by hand in very hot water so it has no water spots. dishwasher soap residue or antispotting agent films on it. Draw a glass of tap water and insert the meter. What meter do you have by the way? Let the reading stabilize and write it down. Next, and very important, triple rinse the glass and meter in RO/DI or in your case since you suspect a problem, pick up a gallon jug of distilled water and use that until you figure it out.
Next draw a sample of RO only water before the DI in the glass, take it directly from the 1/4" line leading between the RO membrane down to the DI filter, disconnect it from the DI and insert the meter, let it stabilize and triple rinse the glass and meter in the distilled water. Write the reading down.
Finally draw a glass of RO/DI directly from the filter, not a storage container or ATO, insert the meter, let it stabilize and write it down. Triple rinse the meter and glass, cap the meter and turn the glass upside down so it stays clean for next use.
What are the three readings?
What is your water pressure and water temperature? Have you vere tried blending or tempering hot and cold water to increase the temperature? What is your excat measured waste ratio? Do you have CO2 in your water that you are aware of? What is your water source, ie well, surface, etc? What membrane do you have and are you certain it is installed correctly and inserted all the way? Did you disinfect the system while you ahd it apart for filter changes?
Use a squeaky clean clear glass drinking water glass, washed by hand in very hot water so it has no water spots. dishwasher soap residue or antispotting agent films on it. Draw a glass of tap water and insert the meter. What meter do you have by the way? Let the reading stabilize and write it down. Next, and very important, triple rinse the glass and meter in RO/DI or in your case since you suspect a problem, pick up a gallon jug of distilled water and use that until you figure it out.
Next draw a sample of RO only water before the DI in the glass, take it directly from the 1/4" line leading between the RO membrane down to the DI filter, disconnect it from the DI and insert the meter, let it stabilize and triple rinse the glass and meter in the distilled water. Write the reading down.
Finally draw a glass of RO/DI directly from the filter, not a storage container or ATO, insert the meter, let it stabilize and write it down. Triple rinse the meter and glass, cap the meter and turn the glass upside down so it stays clean for next use.
What are the three readings?
What is your water pressure and water temperature? Have you vere tried blending or tempering hot and cold water to increase the temperature? What is your excat measured waste ratio? Do you have CO2 in your water that you are aware of? What is your water source, ie well, surface, etc? What membrane do you have and are you certain it is installed correctly and inserted all the way? Did you disinfect the system while you ahd it apart for filter changes?
NO, NO, NO.
Never blend hot and cold to warm the water up!
Remember being in a nice warm shower and someone flushes the toilet or starts the washing machine? You got your tush scalded.
The same thing happen to the RO membrane and it cannot stand any water over 113 degrees which isn't all that hot. Besides that cold water treats better since it is more dense or less viscous so the RO TDS will be lower and the DI will last longer.
More pressure is great, membranes love pressure, the higher the better up to around 150 psi. The weak point is the housings and fittings so I set my booster pump at 95-100 psi.
Never blend hot and cold to warm the water up!
Remember being in a nice warm shower and someone flushes the toilet or starts the washing machine? You got your tush scalded.
The same thing happen to the RO membrane and it cannot stand any water over 113 degrees which isn't all that hot. Besides that cold water treats better since it is more dense or less viscous so the RO TDS will be lower and the DI will last longer.
More pressure is great, membranes love pressure, the higher the better up to around 150 psi. The weak point is the housings and fittings so I set my booster pump at 95-100 psi.
