TDS meter reading

Red Sea · 06/17/2019, 02:25 PM

Hi all hope you are well. I purchased a handheld TDS meter and checked reading from ro unit and it read 2. When I then took the reading from top up container I store it in (plastic food grade) it read 9. Is this reading ok and is this normal ?

mcgyvr · 06/17/2019, 03:43 PM

Do you have a di stage or just ro membrane?
2 is perfectly fine for the output of the ro membrane but is starting to be an indicator that your di stage (if equipped) is ready to have the resin changed.. If you dont have di then there is nothing to do..

And yes slightly higher tds in a storage bin is totally normal...Likely just dust from the air,etc...

Red Sea · 06/19/2019, 04:16 PM

Hi, thanks for your reply. I do have a di attached . I am getting a reading of 2 after I have change both filters and the di media.

outssider · 06/19/2019, 05:39 PM

after di, your reading should be -0-. what is the reading after ro but before di ?

mcgyvr · 06/20/2019, 04:27 AM

With fresh DI stage your reading should be zero provided at least that....
1-You are measuring after the unit has been running for a few minutes
2-You are sampling from a perfectly clean glass as quickly as possible or the probe is built into the tubing.
3-You have properly packed the DI resin to ensure no channeling is occurring..
4-You have ensured your TDS meter has been properly calibrated and its probe is clean and free of any debris,etc...

06/17/2019, 02:25 PM	#1
Red Sea Registered Member Join Date: Mar 2017 Posts: 7	TDS meter reading Hi all hope you are well. I purchased a handheld TDS meter and checked reading from ro unit and it read 2. When I then took the reading from top up container I store it in (plastic food grade) it read 9. Is this reading ok and is this normal ?

06/17/2019, 03:43 PM	#2
mcgyvr Registered Member Join Date: Sep 2003 Location: North Carolina Posts: 20,050	Do you have a di stage or just ro membrane? 2 is perfectly fine for the output of the ro membrane but is starting to be an indicator that your di stage (if equipped) is ready to have the resin changed.. If you dont have di then there is nothing to do.. And yes slightly higher tds in a storage bin is totally normal...Likely just dust from the air,etc... __________________ Who me?

06/19/2019, 05:39 PM	#4
outssider Registered Member Join Date: Nov 2009 Location: Reseda, Ca. Posts: 1,717	after di, your reading should be -0-. what is the reading after ro but before di ? __________________ Please don't feed the bears because the bears will become dependent on free handouts and forget how to take care of themselves …... Current Tank Info: 75 Gal. Mixed reef mostly sps

06/20/2019, 04:27 AM	#5
mcgyvr Registered Member Join Date: Sep 2003 Location: North Carolina Posts: 20,050	With fresh DI stage your reading should be zero provided at least that.... 1-You are measuring after the unit has been running for a few minutes 2-You are sampling from a perfectly clean glass as quickly as possible or the probe is built into the tubing. 3-You have properly packed the DI resin to ensure no channeling is occurring.. 4-You have ensured your TDS meter has been properly calibrated and its probe is clean and free of any debris,etc... __________________ Who me?

06/19/2019, 04:16 PM	#3
Red Sea Registered Member Join Date: Mar 2017 Posts: 7	Hi, thanks for your reply. I do have a di attached . I am getting a reading of 2 after I have change both filters and the di media.