Does TDS rise when water sits in a container?

[bpnc]

Water is coming out of my RO unit at 17ppm TDS and it goes into a 3.5 gallon plastic bucket with a lid. The lid is tight and only has a hole for hose and wire for the power head that supplies the sump. In the bucket is the Kent Float Valve that allows the water to come into the bucket and shuts off the RO when it is full.

The water comes out of my RO at 17ppm TDS...I just checked it. I emptied the bucket and wiped it dry last Sunday night, now the water is in the bucket is 67ppm TDS???

What would cause TDS to rise?

Thanks,

Bill

 

[IcantTHINKofONE]

pbnc, if TDS counts bacteria and other live things I'm guessing that's what the high count is. if you test the TDS of an aquarium's water it is also high but not necessarily bad.

 

[monkeyboy]

Could any water from your tank have back-siphoned into the resevoir when the top-off pump is off?

 

[bpnc]

IcantTHINKofONE - I am not sure if TDS reads bacteria but it is a possibility.

monkeyboy - No way for a siphon back to the bucket as the hose going to the sump is attached to a bracket with a 90 degree fitting sitting about 10 inches above water level.

Any chance anyone has a TDS meter and could compare their holding tank to the RO output?

Thanks,

Bill

 

[BradR]

Salt will definitely skyrocket your TDS.

 

[PDD]

bpnc,

RO water is very aggressive due to it being in a pure state. Tap water is not, for example. Therefore, RO water will literally attack and extract things from the container, or anything else it comes in contact with (i.e. even the tubing it runs through). That is why the components/tubing/storage containers, etc. are "special" for RO. They do not leach contaminents back into the water.

You probably have seen threads before regarding folks who store their water only in food grade containers for the same reason. I personally don't.

Well, that is how I understand it. HTH