RO/DI unit

[Necsones]

somethings up with my RO/DI unit (6 stage)... i just changed my filters, sediment filter, carbon filter, carbon block filter, DI filter and in-line granular activated carbon filter.. when i just put it on the TDS reads anywhere from 20- 36 then i let it run for a lil bit and goes down to 4.. does this every time i sart it?? anyone have any ideas? and the membrain is a year old.

one question, should the DI be last filter?

 

[Killerdrgn]

yes di should be the last filter. do you have a pressure gauge on this rodi unit?

 

[georgelc86]

Typically it should be Sediment -> Activated Carbon -> Carbon Block -> Carbon Block -> RO Membrane -> DI Resin

 

[Necsones]

no gauge, i gotta see how i have the pre filters hooked up.

 

[House of Laughter]

Nesc,

what TDS meter are you using? try to benchmark with a handheld meter - great $39 bucks (some are cheaper) spent

House

 

[Necsones]

yeah im useing Liquatec hand held.

just so i know i have this set up right..
sediment - first
carbon block - second
next carbon block - third
membrane - fourth
granular activated carbon - fifth
DI resin sixth

the set up came to me with granular activated carbon sixth and di resin fifth

 

[House of Laughter]

All those stages confuse the heck out of me.

All that is needed to obtain "0" TDS in NYC and surrounding areas is a 4 stage unit - I wouldn't use the rest.

Sediment
Carbon
Membrane
DI

If I were to run that UNit I would do the following:

5 Micron Sediment
1 Micron Sediment
Carbon 1
Membrane
DI
6th empty (or 5th depending on which one has a larger capacity for DI Resin)

HTH

house

yeah im useing Liquatec hand held.

just so i know i have this set up right..
sediment - first
carbon block - second
next carbon block - third
membrane - fourth
granular activated carbon - fifth
DI resin sixth

the set up came to me with granular activated carbon sixth and di resin fifth

 

[Necsones]

cool, thanks lol

 

[Necsones]

i just went to fill up a gallon bottle for top off water, and checked the tds before i filled it and it read 20... i let it run for a little while and now reads 5. I have no clue why its doing this.

and about that 6th filter i read up on it and its just a post filter.

 

[House of Laughter]

the change in output isn't uncommon - it takes about 5-10g of water to make the water read "0"

remember, the meters read in parts per million (PPM) and I bet you if you tested a 30g drum it would read "0"

FWIW

House

 

[juiceguy]

it is normal for a RO unit to have a higher TDS when first turned on, RO units work better when running on a regular basis. the turning on/off of the unit lets the water in the unit settle there and pick up stray TDS. you should always check the TDS after running the unit 5-10 minutes, that allows the stray TDS to get caught up in the filters again and yes, the DI should be the last stage in the unit, running the DI anywhere else would only use up the resin faster.