RO/DI TDS question

[Fly n Reef]

I just changed out my carbon/sediment/Hi-S silicate filters on my Kent Marine RODI unit and now my TDS readings are 15ppm. I changed them because the readings were at 2ppm.
I ran the system into a trash can to saturate the new filters until the TDS reading went to zero.
My question is why is it reading so high 24 hours later and what to do with it now?
Thanks,
Fly

 

[NaH2O]

Hmmm...interesting. Karen, when you say the Hi-S filter are you refering to the DI resin cartridge? (I also have a kent marine unit). Did you go with the same gpd cartridges and membrane that you had before? What is the TDS prior to going in the unit (out of tap)? Hopefully, these will help up figure it out.

 

[Scooterman]

Being I just went through some of the same issues ( I have a Hi-S also) My first question is what Micron filters did you get, they make 1 & .5 micron, for the Kent replacements but you may of gotten one with a larger micron filter, this may be the start, also flush your RO unit well, and test again. Just a few thoughts along with Nikki's!

 

[Fly n Reef]

Thanks for the responses.
Yes Nikki the Hi-S is the resin cartridge. My TDS out of the tap is still the same as before 107-115 TDS.
Scooty I got the 1 micron filter and to the best of my knowledge the carbon and resin are the same as before too.
I do not have a flush kit for my RO unit but I did rinse the canisters out and ran several gallons into the trash can and got a zero reading. I assumed that was a true zero. Should I get an add on flush kit? Just out of curiosity I check it this morning and got the 15ppm reading. I don't understand it.
HMMMM!

 

[Scooterman]

Try and re calibrate your TDS meter, unless you already did. Also, try and make some water into another container, or clean that container again, I know If I want a true reading I have to clean the container each time. Maybe try a small amount directly from the unit to a clean glass or something else. I now use the .5 micron prefilters but that shouldn't make for much difference with a basis of 105 to 115 going in. Run a TDS reading after just the two pre filters and see what you get. A flush kit will increase the life of the RO membrane, with your readings it may not be as critical as umm lets say mine at a TDS of 300 to 400 ppm

 

[Fly n Reef]

I am not sure how to calibrate my TDS meter. It is the inline kind. I will need to do some research on that. I did run several gallons through the unit and threw that water out initially.

 

[NaH2O]

I also have the inline TDS meter. I'll look and see if there is anything weird with those. The only thing I can think of with the inline TDS meter is if the prongs get skewed off of being inline with each other. When I set my unit up, I ran the water for about 30 gallons or so. My TDS (pre-filters) is 450-500 range on most days. The only other thought I had was one of the cartridges isn't installed properly, or the wrong micron size.

 

[Fly n Reef]

I did some research on my meter. It claims to be pre-calibrated from the factory and does not need calibration. I am going to try and reseat the cartridges and see what happens there.
Thanks for the info Nikki.
I also shot an email off to Kent Marine but haven't heard back yet. If I find out something useful I will post it.
Karen

 

[Scooterman]

I did run several gallons through the unit and threw that water out initially.

Ok when you make water, does it go straight into a container? I would make sure that container is well cleaned, it can be a major cause. It may be that your filters aren't seated properly, I had a cut lower gasket once, water would bypass the filter but this alone wouldn't be the problem, the last filters are the RO/DI units, one of these may of been contaminated when the initial change has occurred. I know I had a problem with pressure suddenly when I replaced the DI filter, the pressure dropped lower than half. I still couldn't figure that one out because it wasn't too long before that, I had replaced the two pre-filters. Come to figure things out, with my best guess, being I went from 1 micron to .5 micron Pre-filters, they clog up twice as fast lol! So basically I replaced all of them at a cost. Lesson learned but now you have something else problematic with a simple filtration system, so this will be a learning experience. I wrote Kent once & received a reply, wasn't helpful but at least they tried.

 

[Fly n Reef]

Thanks Scooty.
My TDS meter is inline so whether or not the container is clean should not effect the TDS readings since they are not taken from the container but from the RO unit itself. I tried reseating the filters and went to the LFS where I bought it and picked thier brains a bit. I am going to do a little more tweaking and see what happens.
I appreciate your help.

 

[Fly n Reef]

Great news...problem solved. It was a bad O-ring on the resin filter. Yippee. Back to the bliss of zero TDS.
Thanks everyone for your help.
Karen

 

[NaH2O]

Woohoo! I'm glad, Karen. I was just in the utility room looking at my unit. Glad it was something easy. Whew!

 

[Fly n Reef]

Thanks Nikki. Lessons learned again.

 

[Scooterman]

Glad is was easy & didn't cost you like mine, good news!