How long till TDS hit 0

[Cubbies]

I changed out my sediment and carbon block filters last night on my RODI unit. It is only a 4 stage 50GPD unit, nothing huge. TDS was coming out a bit high so I double checked everything was in order. Everything checks out. I don't believe it's the membrane or the DI. The membrane is roughly 9 months and the DI I changed a couple months ago and color hasn't changed yet(it's color changing). My TDS out of tap comes out a bit under 300. When I first put the filters it was coming at around 350. It is now at about 40 but I ran it for 4 hours last night and it's been running for about 1/2 hr this morning. Is this normal. I don't believe it has happened to me before. I was wondering if maybe different filters do this or what. Do any of you run it for a bit before hitting 0? Thanks, Geno

 

[MHG]

It should be at zero in a few minutes of running out the water. I would say more items need to be replaced...

 

[Cubbies]

It should be at zero in a few minutes of running out the water. I would say more items need to be replaced...

I was hoping not to hear that. But I am afraid it just might be true. :hammer: Cause in the past it has gone to 0 right away for me as well if I remember correctly. Thanks

 

[Jeremy B.]

Your DI is done if it's coming out at anything above 0. Good DI water should always have a reading of 0, when this starts to creep up to 1 or higher, then it's time to change that filter out. We have replacement color-indicating resin here:

http://premiumaquatics.com/aquatic-supply/ro-filters.html

You should be able to refill your existing DI cartridge, that way you save $5 everytime it's exchausted, plus you don't have to keep throwing that cartridge away.

What is your output TDS coming out of the membrane, before it goes into the DI?