TDS reading and questions i have

[mattseattle]

ok i received the TDS meter I ordered and did some readings:

TDS water out of the faucet read 43
TDS water out of the membrane read 0
TDS water out of the DI filter read 2

i'm assuming that means the DI filter is spent and leaching stuff back into the water.

so my question is since the reading right out of the membrane is 0 is there a need to replace the DI filter? also, is my assumption correct when I'm thinking the DI filter is spent and leaching stuff back into the water?

thanks

 

[saltwater-nut]

I think you've hit the nail on the head.

Hard to believe your tap water is that good! My tap water reads 143ppm. I was told its good

BTW,I'm not convinced that our tanks require 0 TDS readings.

 

[mattseattle]

yeah i thought maybe the TDS meter was wrong so i re-calibrated it. it was off by 1 (or else i calibrated it wrong). tap was is about 44, water out of the membrane is 0 but i did get a 1 reading once. i didn't retest with the DI filter. i took it out for now. i just made a few gallons of water and tested it in a bucket and it tested as 1.

i'm assuming 1 is good enough to use for reef water.

 

[Macbeth417]

How old is the DI cartridge??

Matt I did the same thing with my TDS meter on my tap read 45, so I recalibrated and still reads 45 : P .
Just use your RO output until new DI gets there. My RO usually read between 1 and 2... after DI always 0.

-Erik

 

[mattseattle]

well i just bought this RO/DI unit from someone on here...it was used. he said it had about 500 gallons run through it. i read the DI cartridges are usually only good for 400 gallons so i am sure it was exhausted. after testing with my new TDS meter i know it's exhausted. my TDS actually went up a point or two when the DI cartridge was installed. I'll order a new one.

 

[kevinpo]

The readings on your TDS meter are about right for you west side guys Most of your water is from rain and has limited contact with the ground. The water from the aquifer on the east side runs 86 ppm at the end of summer and 168 ppm in the spring. 1 ppm is certainly good enough to use, even 2-3 is good.

Regards,
Kevin