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Boiler water analysis question: 35 mg/L TDS is great, right?

My water company recently issued a report that states an annual average Total Dissolved Solids (TDS) of 35 mg/L. Question: This is good, right? Somewhere I read that ideal boiler water will contain less than 500 mg/L, so I'm in pretty good shape, right? Also, average PH is 7.4. That's a bit low for a steam boiler. Although I have PH test strips, it's hard to test for me since I have 1 Steam Master tablet dissolved in the boiler, and that tints the water a very light purple, making it hard to read a PH strip. However, I assume that with one Steam Master added to boiler water that starts from the tap at 7.4 PH, I'm probably fine on the PH scale, too, right?


  • ethicalpaul
    ethicalpaul Member Posts: 3,129
    edited February 2019
    It's probably not the tint that's making it hard to read, it's probably the relatively high ph that makes the PH strip very dark (if it's anything like my water). The scale on my strips is very hard to discern between 9, 10 and 11. 10 and 11 especially are nearly indiscernible on the provided scale.

    This comes from a place of extreme ignorance, but that never stops me haha: I'm sure the TDS from any municipal water source is fine for any boiler. It's what happens to the water after it's been circulating in your boiler for a year that may be at issue.
    1 pipe Peerless 63-03L in Cedar Grove, NJ, coal > oil > NG