TDS in ATO Container

[bonomo53]

Is it normal to get some tds in my ATO container? Took a reading on Monday and it was 0. Just took it again today and its almost empty but it reads 20 on the the TDS meter. Its an custom acrylic container and the line sits in my sump around 3 inches above the water.

 

[Samina]

Is it normal to get some tds in my ATO container? Took a reading on Monday and it was 0. Just took it again today and its almost empty but it reads 20 on the the TDS meter. Its an custom acrylic container and the line sits in my sump around 3 inches above the water.

I would assume that over the course of the week, there would be a bit of dust or other particles that end up in the container. Even if it’s mostly enclosed, there’s still openings in which dust can get in through. Do you have a lid on the container?

 

[bonomo53]

I would assume that over the course of the week, there would be a bit of dust or other particles that end up in the container. Even if it’s mostly enclosed, there’s still openings in which dust can get in through. Do you have a lid on the container?

Yes lid it almost completely sealed now i covered all the openings last week. It also sits in a cabinet.

 

[Randy Holmes-Farley Verified Community Expert]

Is it normal to get some tds in my ATO container? Took a reading on Monday and it was 0. Just took it again today and its almost empty but it reads 20 on the the TDS meter. Its an custom acrylic container and the line sits in my sump around 3 inches above the water.

Yes. Normal and not a concern.

As mentioned, salty dust and droplets in the air easily raise it.

 

[bonomo53]

Yes. Normal and not a concern.

As mentioned, salty dust and droplets in the air easily raise it.

Thank you Randy!

 

[Randy Holmes-Farley Verified Community Expert]

You're welcome.

Happy Reefing.

 

[Idoc]

Yes. Normal and not a concern.

As mentioned, salty dust and droplets in the air easily raise it.

I must not be understanding something about TDS. If it's not a problem for the TDS to raise to 20 when its in the ATO Reservoir and then going into the aquarium, then why are we so concerned and must change DI resin or RO membrane on our RODI systems when the output goes from zero to a few ppm?

My TDS post resin is zero. I store my RODI water in a Brute trashcan. It can be in there a week or so as I use it and then keep adding to it. I can only imagine how high my TDS is in there after sitting the week or so! I don't have a mobile tds meter...but it kind of sounds like it doesn't matter?

 

[Randy Holmes-Farley Verified Community Expert]

I must not be understanding something about TDS. If it's not a problem for the TDS to raise to 20 when its in the ATO Reservoir and then going into the aquarium, then why are we so concerned and must change DI resin or RO membrane on our RODI systems when the output goes from zero to a few ppm?

My TDS post resin is zero. I store my RODI water in a Brute trashcan. It can be in there a week or so as I use it and then keep adding to it. I can only imagine how high my TDS is in there after sitting the week or so! I don't have a mobile tds meter...but it kind of sounds like it doesn't matter?

That's a good question with a simple answer.

TDS should be used to ensure that your RO/DI is working properly, not to decide if water is good or bad. It is measure of all ions in the water.

In tap water, TDS will be by far be dominated by things that would be fine to add to your reef tank (sodium, calcium, chloride, carbonate, etc.). Thus we really do not care about the TDS.

But there are some things in tap water we care about. Copper, silicate, ammonia/chloramine, etc.

The easiest way to know that the RO/DI is removing those bad things is just to ensure that it is removing everything, and that is what TDS tells us. We want 0 ppm TDS or close to it.

Then you take that 0 ppm TDS water, and later it gets exposed to salty dust in the air, CO2 from the air, salty contaminants left in a reservoir from a previous use, etc. None of those are likely to be a problem (assuming a normal situation) so even though TDS rises a bit later, we are making the assumption that those things raising it are not typically the bad actors we were trying to remove in the first place.

 

[Idoc]

That's a good question with a simple answer.

TDS should be used to ensure that your RO/DI is working properly, not to decide if water is good or bad. It is measure of all ions in the water.

In tap water, TDS will be by far be dominated by things that would be fine to add to your reef tank (sodium, calcium, chloride, carbonate, etc.). Thus we really do not care about the TDS.

But there are some things in tap water we care about. Copper, silicate, ammonia/chloramine, etc.

The easiest way to know that the RO/DI is removing those bad things is just to ensure that it is removing everything, and that is what TDS tells us. We want 0 ppm TDS or close to it.

Then you take that 0 ppm TDS water, and later it gets exposed to salty dust in the air, CO2 from the air, salty contaminants left in a reservoir from a previous use, etc. None of those are likely to be a problem (assuming a normal situation) so even though TDS rises a bit later, we are making the assumption that those things raising it are not typically the bad actors we were trying to remove in the first place.

Thanks, Randy! Now I finally understand! Great answer!

 

[Randy Holmes-Farley Verified Community Expert]

Glad to help!

Happy Reefing.