pumarjr
Reef-a-Holic!
I just changed all filters on my RO/DI Unit, membrane, Carbon, sediment, DI. i ran about 10 gal of water thru it and it's still showing 2 on my tis meter. anyone have an idea as to why? Do I need to flush my DI Filter?
R/O Unit, Still Showing 2 TDS
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MitchReef
Well-Known Member
If that is the output TDS (after the DI) it sounds like you got bad resin. The only way you should have 2 after the resin is if it's bad or if there isn't a full DI chamber. It should be filled all the way so no water can channel through it. If you are measuring the TDS at the outlet of the RO membrane that is a good reading.
What exactly did you replace, how did you replace them, did you systematically flush each step one at a time so as to not contaminate the next filter in line, did you send 3-5 gallons of RO only wate rto waste before installing the DI and di you flush a fresh gallon of RO or so of RO water through the DI before taking the readings?
What are you testing with, inline or handheld? If its inline are the probes inserted fully and rotated in the correct direction? What is the temperature of your wate rand what is the temperature of the room it is in? Inlines are not temperature compensated so can be off if they are not the same since it senses air temp and not water temp.
If its a handheld TDS meter what are you using to capture the water and test it in? Is it clean and triple rinsed with RO/DI between each test? You are not testing from a storage container or ATO are you?
What are your tap water, RO only water and RO/DI TDS readings? What is your exact measured waste ratio not what they claim it to be? This can be measured with a measuring cup and clock or watch.
What is your water pressure? What RO membarne do you have, brand and size? What DI resin are you using? How old is the resin, was it shipped and stored sealed in an airtight bag out of direct light and in a coll place like the refrigerator? Is the DI vertical or horizontal and its it packed properly so there is no channelling or short circuiting?
As you can see there are lots of questions to be answered, RO/DI is not plug and play as many seem to believe and lots of things have an effect on its GPD and TDS.
What are you testing with, inline or handheld? If its inline are the probes inserted fully and rotated in the correct direction? What is the temperature of your wate rand what is the temperature of the room it is in? Inlines are not temperature compensated so can be off if they are not the same since it senses air temp and not water temp.
If its a handheld TDS meter what are you using to capture the water and test it in? Is it clean and triple rinsed with RO/DI between each test? You are not testing from a storage container or ATO are you?
What are your tap water, RO only water and RO/DI TDS readings? What is your exact measured waste ratio not what they claim it to be? This can be measured with a measuring cup and clock or watch.
What is your water pressure? What RO membarne do you have, brand and size? What DI resin are you using? How old is the resin, was it shipped and stored sealed in an airtight bag out of direct light and in a coll place like the refrigerator? Is the DI vertical or horizontal and its it packed properly so there is no channelling or short circuiting?
As you can see there are lots of questions to be answered, RO/DI is not plug and play as many seem to believe and lots of things have an effect on its GPD and TDS.
OP
OP
pumarjr
Reef-a-Holic!
i noticed a strange almost kinda peauntty flavor. when I replaced the filters as stated in the first post, I changed all four filters. no I did not flush the membranes one at a time, the temp is well within range, and i had ran about 15 gal thru it and was still showing 4-5 on my HANDHELD TDS meter. I just installed my old DI filter to see if it lowers. i'm running 5 gal thru the canister first before I test it.
We need real number, not things like "iwell within range" if you would like some accurate advice. What are you testing the TDS in and is the TDS meter accurate? I suggest a nice squeaky clean clear glass drinking wate rglass, washed by hand in very hot water. Dishawashers leave a film and water spots which register as TDS. If you suspect the RO/DI is producing TDS then buy a gallon of distilled water at the grocery and triple rinse the glass and meter before use. Check that the meter is registering 0 TDS at this point with the distilled water, at most I would expect 1 or 2.
Now fill the glass with tap water and insert the TDS mete rletting the reading stabilize, temperatures need to stabilize between the probes and water. Record the reading and triple rinse the glass and meter in distilled water again.
Next, fill the glass with RO only water after the unit has been running at least 5 minutes. If you do not have a DI bypass valve or ROsample port remove the 1/4" line that leads from the membrane down to the DI filter at the DI end and fill the glas from there. Immerse the meter letting the reading stabilize, record the results and do another triple rinse with distilled water.
Finally, stick the 1/4" line back on the DI filter, let it run a minute or two more and fill the glass with RO/FI water and insert the meter. Let the readings stabilize, record the results. do a final triple rinse, cap the meter so it stays clean and put the glass away upside down so it stays clean for next time.
Now, what are the three TDS readings?
What is the wast ratio using a measuring cup and watch timing first the waste flow for one minute then the treated flow for the same one minute period?
What is the water temperature?
What is the pressure?
All these things have a major effect on membrane performance and all must be known for accurate troubleshooting. Without one or all its a shot in the dark and I don't like guessing at things and making incorrect recommendations based on a guess or supposition. I am glad to help but need more information.
Did you disinfect or clan the housings and system while you had it apart? This is critical as bacteria and viruses can grow inside housings since you are providing the perfect environment, warm water, no chlorine since the carbon adsorbs it and light if you have clear housings.
Also have you ever run warm water through the system or used/stored it in a non climate controlled place like outside? This is hard on a membrane and filters and could be part of the original problem of odors or tastes. I have witnessed extreme bacteria counts in RO systems which were not maintained, some requiring hospitalization or medical care. Its no laughing matter.
The reason it is critical to flush each filter individually is sediment filters contain antimicrobial coatings, glues and binders which can foul the carbon if not flushed first. The carbon contains dust and fines which can foul the membrane and may not flush off its surface. The membrane also contains antimicrobial coatings and treatments which require flushing of 3-5 gallons so they do not foul the DI resin wearing it out and DI resin require a flush of 2 or 3 bed volumes to rinse the coatings they are shipped in. Again this is very important and often overlooked causin gpremature failure and poor performance.
The waste ratio is critical and needs to be 4:1 or very close to it to keep the membrane fresh and clean so it performs well. If its too low the TDS builds up and solidifies on the membrane surface until it fails and cannot be rinsed away without chemical treatments. Warm water is bad as membarnes are wound and glued together and anything over 113 degrees can melt the glue so them become delaminated. It only takes a minute or two.
Now fill the glass with tap water and insert the TDS mete rletting the reading stabilize, temperatures need to stabilize between the probes and water. Record the reading and triple rinse the glass and meter in distilled water again.
Next, fill the glass with RO only water after the unit has been running at least 5 minutes. If you do not have a DI bypass valve or ROsample port remove the 1/4" line that leads from the membrane down to the DI filter at the DI end and fill the glas from there. Immerse the meter letting the reading stabilize, record the results and do another triple rinse with distilled water.
Finally, stick the 1/4" line back on the DI filter, let it run a minute or two more and fill the glass with RO/FI water and insert the meter. Let the readings stabilize, record the results. do a final triple rinse, cap the meter so it stays clean and put the glass away upside down so it stays clean for next time.
Now, what are the three TDS readings?
What is the wast ratio using a measuring cup and watch timing first the waste flow for one minute then the treated flow for the same one minute period?
What is the water temperature?
What is the pressure?
All these things have a major effect on membrane performance and all must be known for accurate troubleshooting. Without one or all its a shot in the dark and I don't like guessing at things and making incorrect recommendations based on a guess or supposition. I am glad to help but need more information.
Did you disinfect or clan the housings and system while you had it apart? This is critical as bacteria and viruses can grow inside housings since you are providing the perfect environment, warm water, no chlorine since the carbon adsorbs it and light if you have clear housings.
Also have you ever run warm water through the system or used/stored it in a non climate controlled place like outside? This is hard on a membrane and filters and could be part of the original problem of odors or tastes. I have witnessed extreme bacteria counts in RO systems which were not maintained, some requiring hospitalization or medical care. Its no laughing matter.
The reason it is critical to flush each filter individually is sediment filters contain antimicrobial coatings, glues and binders which can foul the carbon if not flushed first. The carbon contains dust and fines which can foul the membrane and may not flush off its surface. The membrane also contains antimicrobial coatings and treatments which require flushing of 3-5 gallons so they do not foul the DI resin wearing it out and DI resin require a flush of 2 or 3 bed volumes to rinse the coatings they are shipped in. Again this is very important and often overlooked causin gpremature failure and poor performance.
The waste ratio is critical and needs to be 4:1 or very close to it to keep the membrane fresh and clean so it performs well. If its too low the TDS builds up and solidifies on the membrane surface until it fails and cannot be rinsed away without chemical treatments. Warm water is bad as membarnes are wound and glued together and anything over 113 degrees can melt the glue so them become delaminated. It only takes a minute or two.
