Fluoride Addition Calculator

It's the U.S. Public Health Service's 2015 recommendation for community water fluoridation, which set a single nationwide optimal concentration of 0.7 mg/L to maintain the cavity-prevention benefit of fluoridation while limiting the risk of dental fluorosis. That recommendation replaced the agency's earlier 1962 guidance, which had ranged from 0.7 to 1.2 mg/L depending on a community's average outdoor air temperature.

Each chemical carries a different fluoride-ion content by weight — sodium fluoride at 45.2%, fluorosilicic acid at 79.2%, and sodium fluorosilicate at 60.7% — and the feed-rate formula divides the needed dose by that effective fluoride content (adjusted for purity). A chemical with less fluoride per pound requires proportionally more pounds fed to reach the same mg/L target, which is why switching chemicals changes the lbs/day output even when Target Fluoride Level stays the same.

Fluorosilicic acid is normally delivered as a 23% liquid solution rather than a dry powder, so its feed rate is converted from pounds to gallons using its specific gravity. Sodium fluoride and sodium fluorosilicate are solids that the calculator assumes get mixed into a 2% saturator solution before dosing, which is handled through the separate solution feed rate calculation instead.

It compares your Target Fluoride Level against the 0.6-1.0 mg/L range still used as a compliance band, flagging whether your target is within range, below the recommended minimum, or above the recommended maximum. This checks only your target input, not your natural fluoride level or actual dosed output, so it's a target-setting sanity check rather than a live compliance measurement.

No — it's a simple 30-day planning buffer that multiplies your daily feed rate (in lbs or gallons depending on the chemical) by 30 days. Actual storage sizing in practice should also account for delivery lead time and supplier truck minimums, which this calculator doesn't factor in.