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Aquarist Forums => Equipment / DIY => Topic started by: NjOyRiD on January 23, 2011, 06:32:54 PM

Title: TDS meter on my RODI
Post by: NjOyRiD on January 23, 2011, 06:32:54 PM
i'd like to know if I isntalled my tds meter at the right spot
check my video (http://www.youtube.com/watch?v=Cu0Tue4_QxU&feature=feedu)

its reading .21 ppm
thanx for the help
Title: Re: TDS meter on my RODI
Post by: RossW on January 23, 2011, 07:28:07 PM
It looks like you have it on your in/tap and out.  I am not sure where you measured 21.

IMHO, it is interetsing to know what your water is coming in at from your tap but I prefer to know what it is going into my DI resin, after the RO, and what is after the DI resin.

Ratio between tap and after RO should be somewhere close to 97% I think.  This will tell you when your RO membrane(s) are spent and need replacing.

Coming out of your DI resin should be < 2.  If it is >2 I would change my DI resin.

In my case, I am about 520 from the tap, and then 9'sh into my DI resin, and <2 coming out.  I go through DI resin at an amazing rate!
Title: Re: TDS meter on my RODI
Post by: JD on January 24, 2011, 06:47:20 AM
I agree with RossW, put your "in" sensor just after your membrane. Having it there will tell you how the membrane is doing.

My TDS coming in is 350 ish and about 6 to the DI. I go through a DI cartridge about every 200g. Come warmer weather I plan on trying to regen the spent resin.
Title: Re: TDS meter on my RODI
Post by: RossW on January 24, 2011, 07:27:43 AM
I am anxiuos to hear how this goes.  It is something I have considered but never done.

Quote from: JD on January 24, 2011, 06:47:20 AM
Come warmer weather I plan on trying to regen the spent resin.