Wash Water Sanitizer & Dose It Right
Cleans leafy greens
Enter your wash-tank volume, the target free-chlorine ppm and your product's strength to get the chlorine needed and the exact product to add, in grams and millilitres.
Wash-water chlorine dose
Next: add 1,667 mL of product, then verify with test strips and top up — organic load consumes chlorine fast, so re-dose to hold the free-chlorine reading near 100 ppm.
Free chlorine is consumed by dirt and produce, so actual concentration drops during washing; control pH (6.5–7.5) for sanitizer effectiveness and monitor continuously rather than dosing once.
Wash water sanitiser — key facts
- Purpose
- stop cross-contamination in wash
- Target
- ≈ 50–150 ppm free chlorine
- Chlorine (g)
- litres × ppm ÷ 1000
- Product needed
- chlorine ÷ available fraction
- pH
- hold ≈ 6.5–7.5
- Used up by
- soil, sap, plant debris
- Monitor
- test ppm, top up, refresh water
- Privacy
- Runs in your browser; nothing uploaded
Clean wash water, or it spreads what it should remove
A wash tank touches every piece of produce that goes through it, so dirty water doesn't clean — it spreads rot and pathogens across the whole batch. Dosing the water with chlorine to a target free-chlorine level, commonly 50–150 ppm, keeps it sanitary so the wash removes soil and microbes instead of moving them around. The amount of product you add depends on the water volume, the target ppm and how strong your chlorine product is.
This tool gives the chlorine needed and the product to add — in both grams and millilitres — from your tank volume, target ppm and product strength. Use it to dose accurately, avoid wasteful over-chlorination, and keep your pack-house wash safe; remember to monitor the free chlorine and refresh the water as it loads up with debris. Pair it with the Drip Chlorination, Cold Storage Shelf-Life and Fruit Waxing tools for a full post-harvest plan.
Dose accurately
Hit your target ppm without guessing.
Stop cross-contamination
Keep the wash from spreading rot.
Avoid waste
Use enough chlorine and no more.
Grams or millilitres
Dose powders or liquids the easy way.
Frequently Asked Questions
Why sanitise produce wash water?+
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.
How much chlorine do I need?+
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.
What ppm of free chlorine should I target?+
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.
What's the difference between grams and millilitres of product?+
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.
What is available or free chlorine?+
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.
Why does chlorine get used up, and how often should I refresh?+
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.
Can I over-chlorinate?+
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.
Does this work for any product or unit?+
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.
Is this a substitute for a food-safety plan?+
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.