DI Cartridge went bad after 3 months?

[DAvis]

I have been using about 25 - 30 gallons of RODI water per week in my various aquaria. The system is a Pure Flo 50gpd. I know there is better and cheaper perhaps, but it works for me and the cartridge replacement is fairly cheap. I have a cheap dual TDS meter installed after the RO and the second after the DI. Yesterday I noticed, while the post RO probe read "0", the post DI was up to a value of 18! I usually replace cartridges as soon as double digits are hit.

My question is, why did my DI resin crap out after only 3 months? My RO membrane is about 2 years old, but 'seems' fine. Any thoughts?

Thanks!

 

[DAvis]

Thanks!

 

[little_fish]

sorry, I have no idea. It could have something to do with how many ions your water has in it coming from the tap.

 

[Waddi]

Does your water come in hot, how fast, what pressure you holding in there? So on, but i put my bets on bad resin, sometimes it can go off, especially if air has reached it.

 

[DAvis]

sorry, I have no idea. It could have something to do with how many ions your water has in it coming from the tap.

Not too bad as city water goes, 225 ppm. I have a breakdown somewhere of the various minerals and their %. Usually fairly stable, except for high chlorine/chloramine after significant rainfall (of which we've had a lot these past few months! Hmm....maybe you hit on something little fish) Thanks!

Does your water come in hot, how fast, what pressure you holding in there? So on, but i put my bets on bad resin, sometimes it can go off, especially if air has reached it.

Water comes in ground temperature, which in central NY is 70's mid summer and drops to upper 40's in the dead of winter. Pressure is decent, though I don't have a gauge. My 50 gpd unit gives me from 30 to 50 gpd rates, depending on time of year and time of day (temp and pressure, respectively). You might be right about the bum resin. Thanks

 

[little_fish]

Well those TDS meters can only read the amount of dissolved solids in the water, they cant measure the ions in your water which are what your DI resin takes care of. So if you have lots of ions in your water, your DI resin would poop out faster

 

[Buckeye Field Supply]

I have been using about 25 - 30 gallons of RODI water per week in my various aquaria. The system is a Pure Flo 50gpd. I know there is better and cheaper perhaps, but it works for me and the cartridge replacement is fairly cheap. I have a cheap dual TDS meter installed after the RO and the second after the DI. Yesterday I noticed, while the post RO probe read "0", the post DI was up to a value of 18! I usually replace cartridges as soon as double digits are hit.

My question is, why did my DI resin crap out after only 3 months? My RO membrane is about 2 years old, but 'seems' fine. Any thoughts?

Thanks!

Some things to think about:

1. High CO2 in your well water
2. Very little chance your RO water is 0 ppm TDS. Do you have your "in" and "out" probes switched?
3. Are the probes aligned (twisted) properly?
4. Low water pressure
5. Frequent on/off cycling of your RO system
6. Low rejection membrane?

Russ

 

[Buckeye Field Supply]

Well those TDS meters can only read the amount of dissolved solids in the water, they cant measure the ions in your water which are what your DI resin takes care of.

Hmm. Ions are conductive, and it is this conductivity that the TDS meter measures.

Russ

 

[DAvis]

The problem was my TDS meter. When I thought it was reading "5", it was actually over 100ppm!!! This was confirmed by another tds meter. My RO membrane had apparently been bad for quite sometime, and because of the bad meter, I didn't detect it. I had a horrible bloom of hair algae, that I couldn't explain with any water quality issues. Well, I found the culprit, a tds meter that couldn't be calibrated to the test solution it was so far out of whack!

Thanks for all who have helped! Word to the wise - check and calibrate your tds meter! :shock:

 

[BL1]

I'm glad you figured out the problem Davis, I can't say I'm too surprised though average lifespan for those membranes is usually about a year.