Dosing Calculator | Southwest Water Innovations LLC

Your Batch

Water Volume

How dirty is the water?

Coagulant

PAC — Polyaluminum Chloride (30% active) PFS — Poly Ferric Sulfate (20% active)

Add bentonite clay

What's mostly suspended in the water?

Organics — sewage, food waste, biosolids (→ CPAM) Dirt, silt, or general inorganic turbidity

PAM Grade

Non-ionic (NPAM) — recommended default Anionic (APAM) — try this if NPAM underperforms on iron-rich soils

Estimated pH Modifier

Recommended Amounts

Enter a water volume above to see recommended amounts.

Mixing order matters. Rapid-mix the coagulant (and bentonite, if used) vigorously for 2 minutes, then switch to a slow, gentle stir at 20–40 rpm for 10 minutes while adding PAM, then let it rest undisturbed for 30 minutes. Full details on the dosing instructions page.

Sanitizing After Pre-Treatment

Once the water is clear and settled, dose your sanitizer directly into the clarified water — never into the dry pre-treatment chemicals. Should you elect to use bleach for chlorine, here is the calculation. Uses the same water volume entered above.

Bleach is a strong base and will raise pH — you may need pH Down (citric acid) afterward to bring it back into range. Check with a pH test strip after dosing.

Bleach Concentration

% available chlorine

Target Free Chlorine

ppm (mg/L)

This assumes the water is already clear with minimal chlorine demand — the whole point of pre-treating first. It is not a dose for raw, untreated, or highly organic water, which will consume far more chlorine before reaching a free residual. Verify the actual result with chlorine test strips and adjust.

These numbers are starting points calculated from the dose ranges and active-content assumptions on the dosing instructions page (PAC 30% active, PFS 20% active, PAM 90% active). The bentonite estimate is a rough ratio derived from our kit proportions, not an independently established dose range. The pH modifier figure is a small conservative starting pinch — actual need depends on your water's alkalinity, not its turbidity, so test and adjust rather than relying on this number alone. Always run your own jar test before scaling up. See Our Liability for full terms.