Help w/ DI Canister

[Cord]

Before I begin let me mention that I am new to this hobby. A friend of mine (Ross) recently puchased a DI canister and cartridge from your store to add to my current Coralife RO filter.

 

Prior to adding the DIto the RO, the TDS meter indicated an output of 8ppm. When I initially added the DI canister I placed it before the membrane, which was incorrect. The DI then turned burnt orange (which I thought was an indication of the need to replace) and it then read 3ppm.

 

After realizing it was connected improperly, I susbsequently placed the clean water line from the membrane into the DI and took a sample after it ran for sevral hours; it still read 3ppm.

 

Today I flushed the membrane for an hour and now it is at 2ppm. The RO filter was only purchased a year ago and the first two chambers/media and carbon were just replaced two months ago.

 

Is it possible that connecting it wrong from the beginning exhausted the DI? Any help is appreciated

[johnnybv]

yes adding a high tds water will exhaust the resin very quickly. There are brown and blue beads in the mix when the entire canister is brown the dI needs to be replaced. The di must be the last stage of purification after the membrane. When all cartidges are new and a new membrane then through the DI your tDS should be zero. so if the carbon and sediment filters are new then it sounds like you need a new membrane

[Rosco's Reefs]

Hey John, what color should that DI resin in the cartridge be when brand new and just getting wet? His TDS going in was 168 or 186 (oldtimers disease)

[johnnybv]

It's a mixed bed resin so to save money they only use about half color changing beads, which are blue. So to start you will have a mix of blue and brown, as the resin is used the blues will turn brown, so you should see a definite line of where the color change is. If water of a tds of 180+ went directly into the resin the chances are pretty good it got burnt up very quickly. DI must be the final stage after all filters and the membrane or it will go fast.

 

Also it looks like the membrane is a year old now which is probably at the end of its life.

 

Edited March 8, 2013 by johnnybv

[Cord]

Thanks for the info John. Im not sure what the TDS level of the water would be after entering the first two stages and then entering the DI before the membrane, as I didn't get a reading at that point.

Ross, perhaps we can replace the resin and check the reading. that should tell us if the membrane is shot. But it sounds like even if it is not shot, they have an avg life expectancy of a year, so I will prob start shopping for a new one

[johnnybv]

the carbon and sediment filters are cheap (at least at my store) and membranes should be around 55-60 bucks

I would replace all the filters and check the tds before the DI, if its more than 5-10 then I would do the membrane. The water after the membrane should be below 5 when new, then the DI should bring it the rest of the way down to 0