DI resin question, Crumbletop chime in on it please!

[BuckeyeFS]

OK:
Tap 450
RO:3
DI:0

Might want to check your RO number again - it has to be higher than 3. At 3 that would mean your membrane has a 99.4% rejection rate -- unlikely.

Crubbletop is right - more often than not when folks complain about slow production this time of year it is due to cold feedwater.

If that's the culprit, it will show in your waste to purified water ratio? You want something near a 4:1.

Russ

[Mikeyjer]

Just did the TDS test tonight on my tap water, I guess I remembered it wrong.

Tap-161
RO-3
DI-2

[gsusfreak]

buckeye, my RO comes out exactly at three everytime...hasnt been any lower or higher since ive had it

[BuckeyeFS]

Originally posted by Mikeyjer
Tap-161
RO-3
DI-2

That would mean a 98% rejection rate - still very good.

Keep an eye on your DI numbers...

[BuckeyeFS]

Originally posted by gsusfreak
buckeye, my RO comes out exactly at three everytime...hasnt been any lower or higher since ive had it

To calculate the rejection rate of your membrane - compare the tds in the permeate (3 ppm) to the tds in the feedwater (tap water). You want to see something close to what the membrane manufacturer claims.

So if you live in the an area with tap water at 950 ppm for example, the rejection rate would be 99.7%. This would be unlikely as it is higher than factory spec for membranes used in this hobby.

If you live in New York and your tapwater reads 32 ppm, the rejection rate would be 90.7% - ok for a Filmtec 100 gpd membrane, but too low for other membranes.

Russ

[Mikeyjer]

Originally posted by BuckeyeFS
That would mean a 98% rejection rate - still very good.

Keep an eye on your DI numbers...

I check it every time I make water. I guess it's about time to replace the resin.....