TDS in RO/DI reservoir

[csb]

Out of curiosity, I measured the TDS in my RO/DI reservoir last night... registered as 18!! Coming out of the RO/DI filter, TDS is 0. I do aerate the water in the reservoir, so is a little bit of TDS normal after 24-48 hours in a reservoir with aeration??

[asm481]

What is the container? Might be something leaching from there. Or it is just absorbing from the atmosphere.

[wetone]

I have used my 20 gal RO/DI container to mix up salt when doing large water changes...once the salt is in there, even after rinsing it out...I find some "residue" which will register in the TDS reading...I always disconnect the hose from the RO/DI going into the container and put water into a clean cup for TDS readings......

[csb]

Yeah, fresh water in a clean cup measures 0. Just after the water has been in the reservoir for a bit, it's registering minor TDS. I'm sure it's not anything major... could be various residues I guess. Reservoir buckets are 7 gallon food grade buckets intended for beer brewing, so I doubt there are any chems leaching in. (Yeah, they made a few batches a long time ago)

Cheers.