Liquid bleach vs. Total Dissolved Solids?

[chem geek]

socalKC,

Please don't be scared away by the sarcasm. The "TDS is bad" line is just common. You wanted information and the answer is that you do not need to worry about the TDS level, but you do need to make sure that your salt level (which really measures chlorides and reports it as ppm sodium chloride) is in the range that your SWG requires (varies by mfg. but usually around 3000-3500 ppm or so).

In a plaster/gunite pool with 100 ppm TA, 300 ppm CH and 30 ppm CYA, then the TDS will be at least 185 ppm above the salt level. Usually, it won't be much higher than that because the main component of TDS is salt.

Richard

[waterbear]

The thing we have been trying to say is that the pool industry has blamed TDS for problems in pools that have nothing to do with TDS. I suspect part of that is from the chemical companies that manufacture trichlor because if the word got out that their stabilized chlorine caused the problems in pools it would hurt their sales so they use TDS instead. Bottom line, if you have old water your TDS will be higher than if you have new water. This in itself does not cause problems but if trichlor was used there will also be very high levels of cyanuric acid and that WILL cause problems. If they blame the cyanuric acid it would hurt their sales. The cure for high TDS and high CYA is the same, however...drain and refill!
Don't worry about TDS is all we are trying to say.