got some interesting TDS readings.....

[Naperville Reef]

Tap water 154
Hinckley Springs Purified Water 292
Refrigerator water (has a built in GE water filter that claims to remove 90% of contaminents) 154

funny that the water i have been buying for $1.70/gallon has a much worse TDS reading than my tap water. and i guess the filter in my frige is worthless.

 

[nm354]

when was the last time you changed out the filter on the fridge?

 

[Naperville Reef]

about 6 weeks ago

 

[mhurley]

I'll bet dollars to donuts that GE filter is simply a sediment filter. That does nothing to clearing TDS. An RO membrane and DI resin are the only things that impact TDS. I have a 4 stage TDS meter on my system. I monitor the TDS of water coming in, before the membrane, after the membrane and after the DI. There's virtually 0 difference between the Tap reading and the pre-membrane reading.

However after the membrane and DI, it's 0.

FWIW, my tap in my part of Naperville is 184 TDS...pretty consistently.

Also, is that Hinkley Springs a "Spring" water?...A TDS that high would not surprise me at all for a mineral or spring water. "purified may simply mean the same thing as your fridge...run through a sediment filter. Read the label...For example on a bottle of Dasani (I believe...one of the popular brands), they state that it's run through a Reverse Osmosis membrane. I'll bet ya that TDS is pretty low.

 

[saltyfun]

Here in Oswego my tap is 286ppm, through an ro = 86, throught ro/di = 0ppm

 

[mhurley]

salty,

If that's accurate, your RO membrane is shot and needs to be replaced.

A shoddy RO membrane pulls out a miniumum of 95% of TDS (good ones are in the 97-99% range), so you should be at 14 or lower before your DI. You're eating up DI resin probably fairly regularaly I would guess. Changing out your membrane will slow down your usage of resin.

 

[Naperville Reef]

the label says "purified by reverse osmosis, filtered and ozonated....."

it also says that minerals are added for taste, not sure how much that effects the TDS reading.

 

[jcm1229]

I live in Park Ridge and my tap readings are 216. FWIW, the water from the Dominick "Water Island" and the RO water at the LFS both had readings of 7.

 

[saltyfun]

<a href=showthread.php?s=&postid=7308597#post7308597 target=_blank>Originally posted</a> by mhurley
salty,

If that's accurate, your RO membrane is shot and needs to be replaced.

A shoddy RO membrane pulls out a miniumum of 95% of TDS (good ones are in the 97-99% range), so you should be at 14 or lower before your DI. You're eating up DI resin probably fairly regularaly I would guess. Changing out your membrane will slow down your usage of resin.

Yup, That RO is a my drinking water. My typoon III RO is 3ppm and 0 after the di.

 

[mhurley]

<a href=showthread.php?s=&postid=7308614#post7308614 target=_blank>Originally posted</a> by Naperville Reef
it also says that minerals are added for taste, not sure how much that effects the TDS reading.

It would affect is a TON, so that explains the readings.



saltyfun,

Nice!...I have a Typhoon III as well....It's been a champ for 4 years now.

 

[ykh]

<a href=showthread.php?s=&postid=7308715#post7308715 target=_blank>Originally posted</a> by mhurley
It would affect is a TON, so that explains the readings.

Agreed. TDS stands for total dissolved solid, so the more minerals you have, the higher the TDS will be

For a side experiment, collect some rainwater when it rains next time, you will be surprised how "clean" it is, low TDS Of course, if you are near the city, this might be high due to pollution.