Let’s talk TDS and RO Storage

[WhatCouldGoWrong71]

I have zero TDS coming out of my RODI unit. This was confirmed by both the onboard display and a handheld unit. My unit is automated, with the auto flush valve. This fills into 2 55 G brutes. The lids are never opened and have been nonstop used for about 8 months now.

When I checked the RO water in storage my TDS is 4. I went and checked my two RO reservoirs and was blown away, one tank’s reservoir has a TDS reading of 35, and this tank (knocking on wood) isn’t having any current challenges with what I would consider TDS related issues. This tank is also newer, and has really been doing a decent job battling the wars (wet gulf rock, insane amounts of pods, etc).

My established tank (>4 years running), has for sure been challenging. Some self inflicted (PO4 got away from me last week .18 now better). I have something photosynthetic going on with my sand, wave makers and a couple areas of rock. I say something as I think it is simple diatoms, but it has been going on for 3 weeks or so. My TDS in this reservoir is 15-20. So, I think I am fueling whatever is going on in my tank. I have a healthy pod population, but, perhaps I need to kick it up some. BUT…

I assume I am contaminating my ATO tanks, lately I have been using a bucket to refill vs a dedicated RO hose. So this I can fix. I’m in the middle of setting up a AWC including RO replenishment, so I can get there. What I don’t get is, how am I getting TDS creep in my Brutes? A month ago I replaced all the media RODI unit as I had some hidden channeling in 2 DI containers. However, I flushed both Brutes of any RO that was with in them. Does TDS creep “just happen”?

 

[Sisterlimonpot]

It's possible you're water is absorbing contaminates from the containers or from the air. Do you know what the plastics are for your storage bins? Do you use any arisols around the house? Plug ins? Etc?

 

[WhatCouldGoWrong71]

They are the Brute containers that we all use. My mixing room is off my garage, it is within 10 feet of a water heater, but the brute containers are sealed. But perhaps, that could cause TDS? The containers are food grade per Rubbermaid. My ATO containers are all sealed with exception of a 1/8th vent hole. But, no aerosols or plugins.

 

[edd59]

you only have 0 TDS when it leaves your unit. once it touches other surfaces it goes up. but i dont think its tds like in your supply water. i wouldnt worry about it.

 

[Opus]

you only have 0 TDS when it leaves your unit. once it touches other surfaces it goes up. but i dont think its tds like in your supply water. i wouldnt worry about it.

Agreed. Unless you do your RO making in a sterile environment there isn't really anything you can do. Whatever is making its into your RO storage containers is probably also making its way into your tank.

 

[Jeroen1975]

Also when your unit starts to produce the first water can read a higher tds. If you by chance switch a lot off and on, and you measure tds with the unit running for some time, you buildup tds in the reservoir and measure low tds from the unit. Im not sure if this happens only when di is nearly spent or all the time.

 

[reefthereefer]

They are the Brute containers that we all use. My mixing room is off my garage, it is within 10 feet of a water heater, but the brute containers are sealed. But perhaps, that could cause TDS? The containers are food grade per Rubbermaid. My ATO containers are all sealed with exception of a 1/8th vent hole. But, no aerosols or plugins.

It might be reading 0 but it could be at a ppb and filling up a 55g it adds up. I would get a sample of the rodi and send it off to icp analysis and go from there

 

[Patx]

Personaly, my brute always smell like cat urine...
And tds creep slowly...
I try to wash ( javex etc...) it etc... ain't working.

I use a old 33g tank to store my RO.
Smell nothing and 0tds...