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

[lithivm]

thanks Phil I just posted on that forum.
I ran it for about two hours, also I bought the pump to help with reducing waste water.

 

[Hawkeye]

thanks for what? Now I know why I like this club so much -phyl does all the hard work and people thank me for it. ;D ;D ;D Ok nothing to read here move along...

 

[lithivm]

Sorry to bother you guys on this again....

What are your TDS after RO but before DI?

I get 18PPM after RO my DI filter is not working its actually raising it to 30PPM.

So hows yours?

 

[magic]

It sounds like your membrane is plumbed backwards and your actually flushing the top of it.

 

[lithivm]

if my water is 350ppm and after RO I get 18ppm this is ~ 5% which is fine performance for certain membranes since they can reject 95% - 99% depending on brand and type. I think adding a new DI module will make this water 0ppm.

 

[MikeNapoli]

if my water is 350ppm and after RO I get 18ppm this is ~ 5% which is fine performance for certain membranes since they can reject 95% - 99% depending on brand and type. I think adding a new DI module will make this water 0ppm.

Yeah Lith, I would add another housing or whatnot and see if that doesn't help.

your 18ppm is good enough for now though.

 

[magic]

I have 144 going into the ro unit, 8 coming out of membrane and 0 after di.

Bob

 

[pgordemer]

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?

A few things to check:
1. Do you have a matching 75G flow restrictor on the waste side. (This is usually the problem)
2. Remove and reseat the membrane.
3. A new membrane has a preservative in it, it will take approximately 30 gallons before it is fully saturated
4. The input line pressure needs to be at least 50 PSI
5. Have you calibrated your TDS meter

I have the same membrane, I had TDS 188 raw water in, TDS 2 after membrane, TDS 0 after DI.

 

[lithivm]

Thanks PG that was a good check list.

I have what I think is a flow restrictor, but not sure if its matching. Do you know where I can buy a restrictor for a 75G membrabe?.

 

[pgordemer]

Thanks PG that was a good check list.

I have what I think is a flow restrictor, but not sure if its matching. Do you know where I can buy a restrictor for a 75G membrabe?.

You can get it from airwaterice, or you can get an external one for about $6 for bulkreefsupply.com. It is considered good practice to always replace the membrane and flow restrictor together.

 

[reeferwanabe]

just changed out all my filters and di from the group buy. was at 4 now at 0 yeah