Got new RO cartridges

[tonkadawg]

Yeah, so I got replacement cartridges for the RO unit - new TFC membrane, a 1 micron sediment filter, a 5 micron carbon block, and a color change DI cartridge. When I first turned the unit on with the new cartridges, my TDS was reading in the 60s! It slowly dropped and by bed time it was around 20ppm. I let it run all night and check it this morning. My TDS is still at 10ppm.

This isn't right. Is there anything I can/need to do to get the TDS to drop? Or do I need to take the filters back?

[CAReefer]

The bottom line is the DI cartridge. My effluent leaves the RO unit at around 13 ppm TDS. After the DI chamber is 0. The problem appears to be with the DI cartridge. Are you sure you installed it correctly? Effluent reading of 10 from the RO, IMO is good. What is the TDS of the water from your tap?

[tonkadawg]

Yeah I am pretty sure the DI cartridge is installed correctly. I will double check it tonight when I get home. Not sure what the reading is from the RO - I can check that too. The TDS from the tap is at 175ppm - appx.

Back when the old cartridges were good, I had a 0 TDS reading, so I know it can be done. Just something with the new cartridges.

[CAReefer]

My tap is over 600 so you have plenty of room to spare with the RO unit itself. Where did you get the DI cartridge? I have to buy bulk resin since mine only last about 6 weeks. 340 gallons of water at 80 degrees evaporates a ton. Not to mention the 45 gallons week for water change.

[CAReefer]

Oh, and are you sure your meter is correct? try it in some distilled bottled water to check. Mine isn't adjustable, been lucky so far and has stayed accurate.

[tonkadawg]

got everything from LFS. I want to say it was a Kent brand cartridge.

So it sounds like that after running for as long as I have, I should be seeing a 0 TDS correct?

[CAReefer]

Yup, you should see a TDS reading within an hour or two.

[GTR]

As was already said... I'd look at the TDS meter with distilled water before looking at anything else.

BTW...I'd be dancing in the streets if my input was 175ppm. Ever see the Grand Canyon? All that missing rock and dirt is in my water.

SteveU

[gqjeff]

mines 380 tds pre and 0-1 post RO/DI.. I am going to be getting new membranes aswell.. What do you guys recommend for a 3 stage with dual DI's after the 3 stages?

Jeff

[CAReefer]

I use the Dow Filmtec membranes through Buckeye Field Supply.
http://www.buckeyefieldsupply.com/
I run-
20 micron sediment filter
10 micron sediment filter
5 micron GAC block
1 micron GAC block
75 gpd Filmtec membrane
two color changing DI chambers

Seems like alot, but over all saves me money. The first 2 sediment filters are only a couple bucks apeice and I change them every couple months. GAC and membrane are done once a year. As previously stated, 1st stage DI lasts about 6 weeks, 2nd chamber then rotated into #1 position and new DI into the #2 position.

[tonkadawg]

Are you sure you installed it correctly?

and we have a winner!!! I just got home, pulled the DI cartridge, flipped it around and inside of 5 minutes I had a 0 reading. I am letting it run longer to be sure, but I think that is it. I had pulled my old cartridges to make sure I got the right ones at the LFS - and the new one didn't have any markings, so I had to guess - 50-50 chance right?

I am going to get some distilled water and double check my TDS reading, but it's a new, no calibration needed TDS meter, so I do think it is reading accurately. BUT, as I have learned in the past, you never know till you test!!!

Thanks for everyones help!!!

[CAReefer]

Good deal, glad you found the culprit.

[Detritivore]

kind of off-topic, but how often are you supposed to replace the DI and RO membranes?

[tonkadawg]

I replace mine when ever I see the TDS rise above 5ppm

[nyfireman3097]

WOW insane mine is 49 coming out of tap and i had my filteres they said 0 but they were 2 years old now iits at 1 go figure