r/o di help

[Fishbulb2]

Sounds great. 1-2 tds is very low. Go ahead and hook up the DI.

 

[warr40]

ok.....should i clean out the DI first b/c its been sitting with the old water in it?

 

[Fishbulb2]

I don't think that's necessary. I would just start using it but go ahead and measure the output TDS. I would not think the inside of a DI cannister would be a very appealing environment for anything to grow. It's pretty much void of all nutrients whatsoever.
FB

 

[warr40]

ok cool
-when i hook the DI up rite away i tested the TDS and its now 4-5 ppm wuts wrong?

-another question.....how long can i store the water until its not good anymore........does storing it raise the TDS?

 

[AZDesertRat]

Is that with the old DI or new? If its new did you flush it for a minute or two before taking your readings? You need to pass a couple of bed volumes or canisters full through it before testing. If it is the old it sounds like the DI resin is exhausted. When resin reaches its capacity it leeches weakly ionized contaminants back in to the water stream. A couple of the most weakly ionized substances are silicates and phosphates.

 

[warr40]

the DI is like a week old?

 

[AZDesertRat]

If its a week old, how much water went through it already at at what TDS?

 

[warr40]

10-15g a about 20-25 ppm i think

 

[AZDesertRat]

Should still be good then. I would run it for a few days and see if it settles down. How are you testing the TDS, is it a handheld meter and are you using a squeaky clean drinking water glass with no water spots, detergent spots or anything in it and filling it directly from the RO or DI and not from a storage vessel? Containers can leach contaminants into DI water pretty easy since it is so agressive and wanting to get back to its normal dirty state.

 

[warr40]

ok im retested it back down to 2 i guess it need to get settled


-another question.....how long can i store the water until its not good anymore........does storing it raise the TDS?

 

[warr40]

i was just wondering my drain line goes up about 4 or so feet until it gets out side is this a problem

-also is it normal for the unit to push out 10-12 ppm once it starts up??

 

[AZDesertRat]

RO/DI water will store for a long time provided it is sealed or covered. Since DI is trying to attract anything it can it will gain a small amout of TDS back but if your container is a clean Brute trashcan or drinking water type container its not much of a concern.
As long as the waste isn't restricted its fine if its higher than the unit. Yes its what is called TDS creep and is inherent to all RO membranes.

 

[warr40]

ok thnx