Good and bad dissolved solids

[RGS]

I follow the TFP pool maintenance guidelines and use liquid chlorine and muriatic acid. I do my own water testing but occasionally go to Leslie’s for some tests I can’t do. Today they said my TDS was 3600. They said that was too high and I should partially drain and refill my pool. I last refilled it 2 years ago. I seem to recall an article in TFP that said that TDS can consist of a variety of different solids and that not all are bad for the pool. I think it said that the solids added by bleach will make theTDS go up but that those solids aren’t that bad.
Is this true? Is there a way to tell how much of the TDS is due to bleach, and whether I really need to drain it. I’d appreciate a link to the article or any other info on this

 

[kimkats]

Here is a thread that goes all over this subject What is TDS? I hope this helps!

 

[RGS]

Thanks. I read the TDS thread.

I just ordered the Taylor sodium chloride test kit. I'm thinking that, knowing my TDS is 3600 ppm, if I measure the ppm of sodium, then the difference should be all other things. I know that my CYA is low (currently 25 ppm), so what is left of my TDS should be things other than CYA and sodium. As long as that is low, I should be OK, right?

My CH is 530. Not sure if I should worry about that yet?

 

[Jimrahbe]

RGS,

We don't test for TDS because they just don't matter...

What problem are you having that you want to blame on high TDS?

Thanks,

Jim R.

 

[Donldson]

I think you missed the most important part of that thread:

We can now measure the things that really matter, so we can stop using TDS.

TDS is mostly meaningless nowadays, as is most of the stuff that comes out of the mouth of a Leslie's employee.

 

[RGS]

RGS,

We don't test for TDS because they just don't matter...

What problem are you having that you want to blame on high TDS?

Thanks,

Jim R.

I'm not having any problem that I can see. My post was simply asking whether a TDS of 3600 was cause for concern because the pool store guys that measured it claimed it was too high.

 

[jblizzle]

Simple solution is to stop letting the pool store test your water and fill your head with nonsense

 

[ashtonfitzgerald]

A saltwater pool often has a higher TDS than 3600ppm just in salt alone for the generator to work.

 

[RGS]

I understand that TDS by itself is nothing to worry about. But since I had recently bought the Taylor sodium chloride test kit, I decided to measure the salt. It was 2600 ppm (I don't have an SWG pool, so its just bleach that I use).

For curiosity only (I'm not concerned) I did the following calculations: The Leslies pool test said I had 3600 ppm TDS. I measured 2600 ppm of sodium and about 530 ppm CH. Subtracting those two from the TDS leaves 470 ppm of other stuff. My CYA level was only 30 ppm. Assuming that is equivalent to 30 ppm of dissolved solids (is it?), that would leave 440 ppm of other TDS stuff, which is fairly small. Is that calculation reasonable? Besides the city fill water, I only add liquid chlorine and muriatic acid, never any other chemicals. (The Leslies test showed no copper or iron by the way).

 

[JamesW]

The 3600 ppm TDS is not a valid measurement.

It's based on a misunderstanding of what the test is and how to use the meter.

If you want to compare the K-1766 to an electronic conductivity meter, you have to set the meter to salt, not TDS.

Also, you can't just add the various numbers and expect them to add up to the TDS. It's more complicated than that.