TDS meter Question

[woodycb]

I just got a dual tds meter, I hooked it up and my IN was reading 245ppm and my OUT was 000ppm. My RO filters are a year old. Is it possible to still get a 0 reading. I switched the sensors and I am still getting a 0 reading on the out side. Just wondering if my water supply is that good.
by the way I got the TDS meter from Buld Reef Supply.

 

[kgross]

Yes you can, if it is an RO DI and your DI is not exhausted.

Kim

 

[Jefe12234]

IME those inline meters are not that accurate. They're good for a rough estimate, but mine read my RO as 0 which would have implied an impossibly high rejection rate given my tap water TDS of ~300. I later got a COM-100 which is a much more accurate handheld meter and it gave me a more reasonable reading of 4 or 5 IIRC.

 

[woodycb]

My DI is not exhausted yet. But given the inaccuracy I am still probably still within the recomended levels???

 

[kgross]

I would be willing to bet everything is OK.

Kim

 

[Thoro]

I have a dual inline TDS meter also and I never hooked mine up to the incoming water because we all know the tds reading will be high. Instead I hook my in up to the hose coming out of the Membrane and my out after my DI. The reason for this is I will know when my membrane is starting to exhaust and therefore I know when to change it out.

 

[woodycb]

I thought about doing that too thoro, I wanted to see what my tap water was testing first.

I just find it wierd that my filters are a year old and very discolored that they would still be testing that good.

 

[Buckeye Hydro]

REmember that your prefilters (all the filters before the membrane - typically one or more sediment filters and one or more cabon filters) don't remove tds. Its the membrane, and to a lesser extent, the DI resin that removes the tds.

You are overdue for a prefilter change, and due to sanitize your system.

Russ

 

[woodycb]

Buckeye, I have changed all of my filters now. It is a 4 stage kent marine system. I changed all of the filters except the DI, it is not exhausted yet. My readings are still the same. I try to keep up on the pre-filter changes but I got a little lazy.
What is involved with sanitizing your system, is it hard to do.

 

[Buckeye Hydro]

No - its pretty darn easy:

We recommend sanitizing your RO/DI system at least once per year. Schedule this process at a time when you are planning to replace your cartridges. These instructions apply to water purification systems without a pressure tank. Before you begin assure that you have about an hour available, and that your work area and hands are clean. You’ll be working with household bleach - prepare the work area accordingly.

Turn off the water supply to the system.

Remove all housings and remove all pre-filters and post-filters from the system including sediment filters, carbon filters, in-line filters, and deionization cartridges. Remove the reverse osmosis membrane(s).

Wash housings with a soft brush or cloth in warm soapy water. Rinse thoroughly to remove all soap. Don’t forget to carefully remove and wash all o-rings. Lubricate the o-rings with a small amount of silicone grease and reinstall them.

Fill the first prefilter housings 3/4 full with potable water and one tablespoon of plain, unscented household bleach. With this sanitizing liquid in the housing, screw the housing back on to the system.

Turn on the water supply a bit, allow water to fill the entire system, and assure water is flowing out of the waste line and the purified water line. Place the outlet of the drain tube and purified water tube slightly higher than the system to assure these tubes are full of the sanitizing solution. When the sanitizing solution has reached the outlet of each tube, and with the outlet of each tube placed above the rest of the system, shut off the water supply for 30 minutes.

After 30 minutes, turn the water supply on and assure that water exits the system from both the drain tube and the purified water port. Flush the sanitizing solution from the system for 5 to 10 minutes, or until the strong odor of chlorine can no longer be detected.

Turn off the water supply and install new filters, taking care to flush the filters as appropriate.

We recommend keeping a maintenance record for your system. Record the date of the sanitizing and filter replacement.

 

[woodycb]

that sounds pretty easy. So do you think my numbers on my TDS meter are somewhat right.

 

[Buckeye Hydro]

A feedwater reading of 245 isn't unusual, nor is a DI reading of zero. I can't tell you if the numbers are accurate - might want to check the numbers with another meter if you think your meter is inaccurate.

 

[woodycb]

This is my first TDS meter so I am very unfamiliar with them. Do you recomend a good portable meter.

 

[Buckeye Hydro]

I prefer the handheld models because it allows you to easily take readings in more than two locations. You want to monitor your 1 )tap water, 2) RO water, and 3) DI water.

Handheld models also tend to be more precise.