TDS Total Dissolved Solids - Trip to pool store

holdup1time

Well-known member
Jun 15, 2019
76
Houston Texas
Hi all,

So I went to the pool store today to get some muratic acid.
Took my water in for them to sample so I could get $5 off my acid purchase.
Surprisingly, their results were very close to mine.
They gave me spill on "you have high phosphates and need something to lower that"...I just said no thank you.
Then, he asks me what kind of shock I'm using. I told him I don't use shock...I just keep my chlorine level where it needs to be....however, if I had a need for shock I would use it (like right before I go on vacation to get the FC real high). He then said chlorine alone doesn't sanitize the pool...again, I just said no thank you.
The one test result that I didn't know about was TDS.
He said my TDS is high because I use liquid chlorine.
Don't know if that's true or not....and if it is, how does TDS, if at all, hurt my pool/plaster?
The TDS reading was 2300.
I imagine like CYA, the only way to reduce that number would be to drain some water.
Thoughts?
Thanks!
 

mknauss

Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
27,157
Laughlin, NV
TDS is meaningless. There are certain components that matter. One is calcium, or CH. The other is CYA. TDS also includes salt, which you add with liquid chlorine. It does not influence pool water chemistry.
 

JamesW

TFP Expert
Mar 2, 2011
18,532
Most pool stores don't measure TDS correctly. Ignore their results.

You should track salinity using a K-1766 salt test kit and enter the result in PoolMath because it affects the CSI.

Keep your CSI between -0.3 and 0.0.
 

holdup1time

Well-known member
Jun 15, 2019
76
Houston Texas
Most pool stores don't measure TDS correctly. Ignore their results.

You should track salinity using a K-1766 salt test kit and enter the result in PoolMath because it affects the CSI.

Keep your CSI between -0.3 and 0.0.
Hi James,
I do have the pool math app and track the CSI inputing all my test results....never thought of testing for salt since my pool is not a saltwater pool. Love this site...pool built last summer and no algae yet :) I've totally nerded out on the water chemisty....couldn't live without my Taylor speed stir!