Wash Water Sanitizer & Dose It Right

Wash water is shared between every item that passes through it, so without a sanitiser it becomes a vehicle that spreads rot, soil-borne pathogens and food-safety risks from one piece of produce to the whole batch. A sanitiser like chlorine kills micro-organisms in the water itself, stopping cross-contamination and keeping the wash from doing more harm than good.

It depends on three things: the water volume, the target free-chlorine concentration in ppm, and the strength of your chlorine product. Chlorine needed (grams) = volume in litres × target ppm ÷ 1000. The product needed is that divided by the product's available-chlorine fraction. This tool works out both the grams and, for liquids, the millilitres to add.

For produce wash water, a free-chlorine level of about 50–150 ppm is common, with 100–200 ppm used on harder surfaces and equipment. Within that band, hold the water near neutral pH (about 6.5–7.5) so the chlorine stays in its most active form. Always follow your local food-safety guidance for the exact target.

Powders and granules (like calcium hypochlorite or bleaching powder) are dosed by weight in grams; liquids (like sodium hypochlorite bleach) are easier to measure by volume in millilitres. The tool gives the grams of product and, when you enter a liquid's density or strength, the equivalent millilitres so you can pour the right amount.

Available chlorine is the share of a product that actually acts as sanitiser — a liquid bleach might be 5–12% available chlorine, a powder 30–70%. Free chlorine is what's left in the water ready to kill microbes, as opposed to chlorine already bound up by dirt. You dose to a free-chlorine target and top up as it's used up.

Organic matter — soil, sap, plant debris — reacts with chlorine and neutralises it, so the free-chlorine level falls as you wash dirtier produce. Test the water regularly with strips or a meter, top up to hold the target ppm, and change the water when it gets too dirty to maintain it. Monitoring is as important as the initial dose.

Yes — too much chlorine wastes product, can leave residues and off-flavours, can corrode equipment, and is unpleasant and unsafe for workers. The point of dosing to a target ppm is to use enough to sanitise and no more. Stay within the recommended band and rely on monitoring rather than guessing high.

Yes — enter your tank volume in litres, your target ppm, and your product's available-chlorine strength, whether it's liquid sodium hypochlorite or a hypochlorite powder. The dose maths is the same; only the strength figure changes between products.

No — it's a dosing aid. Safe produce washing also needs the right water quality, pH control, contact time, monitoring and record-keeping under your local food-safety rules. Use this tool to hit the correct dose, but follow proper sanitation guidance and verify free chlorine with a test kit.