Episode Description
“99% trichlor” sounds like a mic-drop statistic, but it’s also one of the most persistent sources of confusion in pool care. We sit down with Bob Lowry to untangle what that number actually means, why “purity” is not the same thing as “chlorine strength,” and how the industry’s use of available chlorine (based on a chlorine gas reference) warps the way products get talked about on the truck and at the counter.
We walk through the real chemistry behind the label: what free chlorine is doing in the water, why the comparison standard matters, and how trichlor’s makeup includes cyanuric acid that builds over time. If you’ve ever heard someone say liquid chlorine is “weaker” or tablets are “the strongest,” this conversation gives you the language and logic to explain the difference clearly to clients and techs without hand-waving.
Then we pivot to cal-hypo, especially the idea that it “doesn’t add much calcium.” Bob breaks it down in practical terms you can use in the field: if you add cal-hypo to raise free chlorine, you are also raising calcium hardness in a predictable way, and that matters a lot in hard-water regions. We also compare how different percentages of available chlorine change dosing, why some cal-hypo tablets can require much more product than trichlor, and how to think about true cost per usable chlorine. You’ll also hear where to find Bob’s resources (pci.org and pccti.online) and how we can help you level up your pool service business.
Subscribe for more pool chemistry myth-busting, share this with a tech who still quotes the “99%” line, and leave a review with the biggest pool maintenance myth you want us to tackle next.
We revisit a classic pool chemistry myth with Bob Lowry and unpack why “99% trichlor” does not mean you are getting 99% chlorine in your pool water. We also run the numbers on cal-hypo side effects so you can predict calcium hardness rise over time instead of getting surprised by scaling later.
• why “99%” on trichlor labels refers to purity, not chlorine content
• how “available chlorine” is a comparison standard tied to chlorine gas
• what actually gets added when you use trichlor, including cyanuric acid
• why cal-hypo steadily raises calcium hardness and how to estimate it with ppm math
• how different cal-hypo strengths and tablet percentages change dosing and cost
• a simple spreadsheet method to compare true cost per equivalent chlorine
• where to find Bob Lowry’s resources and tech bulletins online
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