View Full Version : 3 canister RO/DI filter

12/31/2008, 07:09 PM
My third stage canister the charcoal one has draineed to 3/4 full . If I hold my finger on the blue discharge it fills up . ake finger off hose it drains back out to 3/4 full again. charcoal in canister has started to change color a little but TDS still 0 in and out. Whats going on . I posted on filter guys but no responce.

12/31/2008, 08:35 PM
I beleive the filter your talking about is the DI cart. If it is , I am almost certain that it is normal for that to happen.
Scroll down to (DI not filling - full of air)

All I did was Google di cartridge not filling up.

12/31/2008, 08:37 PM
You probibly have a color indicating cartridge. hen the color fully changes, the cartridge has exhausted.

12/31/2008, 09:07 PM
I'm by no means an RO expert but I understand what your talking about. I have a Spectrapure unit that has the 3rd cartridge and on mine it's the DI chamber. During normal operation it appears only about 3/4 full....the only time it fills up is when my RO storage water float is activated, the mini bladder tank fills, system pressure increases (thus filling the 3rd chamber 100% and then system shuts off......hope this helps......Also, I would think since your tds is 0 I wouldn't worry to much about it....

01/01/2009, 06:03 AM
Just to clairfy I think I spelled that right . Mine is coralreef from DR. Foster & Smith. Does a good job . I'm on municipal water system Good water at the start. Well as good as any water system.


01/01/2009, 06:04 AM
Juat another ? Why was it full up till now when I was usung it ?

01/01/2009, 06:45 AM
last chamber? that's the di resin on mine. when i started it up some air was remaining in the chamber and no matter how long i let it run it wouldn't go away. what i ended up doing at the recommendation of the manufacturer was this: with the system running, unscrew the chamber slowly, only a little, until the water level begins to rise. once the water level is reaching the top of the chamber, and obviously before you end up with a big mess on your hands, screw the chamber back on firmly. this will allow the air to escape the system and should keep the chamber full until you open it back up for cleaning later.

01/01/2009, 08:33 AM
Don't worry. This is normal.
It may never fill. This is not a problem other than the way it looks to you . The reason it is not filling? Air trapped in the filter housing. That air pushes the water up thru the DI cartridge. The water is forced up thru the bottom of the DI the DI cartridge can have just a very small amount of water in the bottom and still do it's job. As the air trapped in the DI filter housing is absorbed, the water level will rise. If you wait a couple of days the air will be absorbed and the level will rise . You can loosen the housing a little, while the unit is making water the water pressure will push the air out of the housing. Once the water level is near the top of the housing re-tighten the housing. Or force it to fill by restricting the pure water valve a little. The DI cartridge is sealed from the top to the bottom edge. This makes sure the water has to enter thru the bottom of the DI forcing it thru all of the resin. The results air no air are the same it just looks weird.