View Full Version : RO/DI what did i do wrong ??

04/10/2009, 09:30 AM
I changed my filters yesterday .
one of the carbon canister i put a Kent CFI mixed resin. and on the top piece which was the taste and odor removal. I put DI (De-Ionized) Filter .

Now When i tested the waste line with my TDS meter i got a 0.00 reading and on my good water line i also got a o.oo reading . I tested the water going onto the rodi i got a 139 reading.. I don't think its the TDS metter its still new.

I think i hookup the lines wrong ??? after changing the filters ??

Can some one please tell me what i'm doing wrong ???

this what i have

and the way its hookup



04/10/2009, 09:37 AM
Did you put the resin in the pre-filter. One carbon filter is generally the pre-filter to remove chlorine to prevent membrane fouling. If so, the di is removing the solids before it gets to the membrane so the waste water has already gone through a di filter. Try putting the resin after the membrane and the correct carbon filter before the membrane. Everything should then be back to normal. The resin will be exhausted in no time if it's upstream of the membrane.

04/10/2009, 09:58 AM
On the last Carbon filter to the far left i put the CFI resin..

Buckeye Hydro
04/11/2009, 07:29 AM
From right to left in your ebay system you should have a
sediment filter
carbon block
carbon block
the up above the bracket to the RO membrane,
then to the clear DI resin cartridge.

tatkinson is correct in his post above.

Some other things to might want to do on that system:
you only really need one good quality carbon prefilter in most cases, not two.

Horizontal DI cartridges are a fundamental design flaw - typically indicative aof a retrofitted drinking water system built overseas and sold to unsuspecting buyers on the auction website. At a minimum, unclip the DI cartridge and orient it vertically with bottom up flow.

Not sure why you are using a pressure tank in your system unless you are also providing RO (not DI) water to a faucet. You don't want water from that tank going through the DI stage.


04/11/2009, 07:05 PM
Yes I do make ro water too, so when i'm making tank water , I should disconect the pressured thank .. And Ok i will stand up the resin. Oh better yet i have another canister , i can put a DI cartridge in it. .

Now i understand how it works... Thank you so much....


Buckeye Hydro
04/12/2009, 05:16 AM
If you are feeding a faucet with water from the tank than you are missing an inline GAC "taste and odor" filter between the tank and the faucet.

You might want to download the directions to our Reef/Residential system to see where to install a check valve so you can leave the tank connected all the time.


04/12/2009, 06:08 PM
Got It .
Thank you