Mineral systems promise softer-feeling water with less chlorine. They do not promise water without chlorine, and the numbers are worth a closer look.
The short answer: FROG says its sanitizing minerals "work alongside chlorine" and keep an ideal chlorine level of 0.5 to 1.0 ppm, with up to 50% less chlorine than the 1.0 ppm minimum it cites for a stabilized pool. The CDC's minimum for a pool with stabilizer is 2 ppm. Decide which number you follow before you buy (our advice).
Part of: Pool Chlorine: Types, Levels and How to Keep Them Steady, our overview of every chlorine question.
What FROG says
- "FROG Sanitizing Minerals® work alongside chlorine to kill bacteria and maintain an ideal chlorine level of just 0.5–1.0 ppm."
- "Lower your chlorine use by up to 50%*", with the footnote: "Compared to the minimum EPA recommended chlorine level of 1.0 ppm for a stabilized swimming pool".
How that compares
| Source | Free chlorine |
|---|---|
| FROG (with its minerals) | 0.5 to 1.0 ppm |
| CDC, pool without stabilizer | at least 1 ppm |
| CDC, pool with stabilizer | at least 2 ppm |
| TroubleFreePool, by stabilizer level | rises with CYA (see the table) |
FROG's level is below both CDC minimums. FROG relies on its minerals working together with chlorine; the CDC's numbers are for chlorine on its own (our reading of the two sources).
What to keep testing
- Free chlorine and pH, at least twice a day when the pool is in use (CDC).
- Stabilizer, because your chlorine target depends on it (TroubleFreePool).
- Whatever the mineral system's own manual asks for.
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Test kit A test kit that reads free and total chlorineFree chlorine and total chlorine are two separate readings. The CDC calls a DPD test kit the most accurate option for home pools; test strips are less accurate. Follow the kit's own instructions.
Sources
- FROG: Fresh mineral water (works alongside chlorine, 0.5 to 1.0 ppm, up to 50% less)
- CDC: Home pool and hot tub water treatment and testing (minimums, testing twice a day)
- TroubleFreePool: Free chlorine and cyanuric acid relationship (chlorine target by stabilizer level)
Sources read on November 4, 2026. Product labels change: the label on the product you buy always wins.
