What are you TDS readings before/after RO/DI?

[lithivm]

In Union my tap water is 350PPM after the RO/DI unit is about 30PPM.

How about you?

 

[sgarron]

I get 300 before and zero after. 30 is too high. Is this a new unit?

 

[roadking05]

That's high. 136 before and 0 after. I always flush the membrain befor every use for 15 sec.

 

[RichT]

after the pre-filters, before the membrane =125. After the DI = 0.

Well water - Cape May

 

[MikeNapoli]

Mine is 233 going in and 3ppm coming out.

Never hit zero before. Hopefully after this AWI group buy I'll get there.

 

[PMolan]

176 In
2~3 After RO
0 After DI

Town Water.

 

[reeferwanabe]

151 before 004 after perhaps I should order from AWI never changed before. about 51/2 months old water general unit RD-102

 

[AnDom1]

162 In and 0 Out after the DI.

I live in Iselin and have a 5 stage unit

Dom

 

[lithivm]

My RO membrane is about 1.5y old, I will try flushing it for some time. I assume 30PPM isn't that bad of a number right?

 

[Carlo]

30 PPM coming out of the unit is normally considered VERY BAD.

Keep in mind that TDS is only a measurement of some things (dissolved solids) and many other things aren't measured that are also getting through the unit probably in equal proportion to the TDS. 30 ppm might be usuable for one person but down right destructive for another depending on what's in the source water. If it's something like calcium or magnesium that's registering on the TDS it's not bad but that's the key. You don't know without extensive water tests especially in the metals department.

The TDS number is only a gauge (not the be all end all number) and usually when the number hits 1 or 2 it's time for at least a DI resin change.

Carlo

 

[Jf2381]

Mine fluctuates one day is 167 the next is 140 but it's always zero out of the RO/DI.

 

[JasonR]

My RO membrane is about 1.5y old, I will try flushing it for some time. I assume 30PPM isn't that bad of a number right?

30 is no good it should be ZERO
flushing might not work
you might have to buy a new membrane
Now is the time to buy one with the AWI group buy going on
How much water do you think you have made with the membrane you have in there

Jason

 

[MikeNapoli]

Just recently I read on this board that you should test your final product in a glass, not plastic, as plastic will skew your reading.

Run your RODI, take the effluent right into a drinking glass, rinse it a few times, then test with your TDS meter. Let us know where it's at after you do that.

 

[Jf2381]

Just recently I read on this board that you should test your final product in a glass, not plastic, as plastic will skew your reading.

Run your RODI, take the effluent right into a drinking glass, rinse it a few times, then test with your TDS meter. Let us know where it's at after you do that.

So the inline readers are no good?

 

[Carlo]

They are OK for a rough gauge but you will probably want something more reliable to do your "official" checking with.

You should ideally have a TDS meter you can calibrate.

Carlo

 

[Phyl]

I think inline is probably more accurate than in a cup, personally. I'd let it run a bit first to be sure that it is freshly made water that you're testing.

 

[reefsandrotts]

Don't know what mine is, in 25 years of reefing I've never used RO water and I have no problems. ???

 

[lithivm]

OK so I just received my new membrane from the group buy its a 75G Filmtec... and I'm still getting 24PPM after RO/DI I changed all prefilters and the DI.

what can be going on?

 

[Phyl]

How long did you let it run for before testing it? What is your water pressure going into the membrane? I would post this in the AWI forum and ask them for assistance. They could probably tell you quite easily what to look at next.

 

[Jabis96]

124 in and 0-1 ppm after