Sprayer Tank Cleanout & Rinse Clean, Crop Safe
Cleans herbicides
Enter tank size, rinse ratio and number of rinses to get the rinse water per rinse, total water and residual herbicideleft after a triple rinse — so the next sensitive crop is safe from carryover.
Sprayer tank cleanout
Next: run 3 rinses using ~20 L each (60 L total) to cut residue to 0%; spray rinsate back onto the treated crop.
Triple-rinsing dilutes carryover geometrically — three modest rinses beat one large flush. Sensitive follow-on crops may need a dedicated cleaning agent, not just water.
Sprayer cleanout — key facts
- Rinse water/rinse
- tank size × rinse ratio
- Total rinse water
- per-rinse × number of rinses
- Residual %
- heel fraction ^ rinses
- Standard
- triple rinse = 3 rinses
- Rinse ratio
- ≈ 10–20% of tank volume
- Switch caution
- hormone & sulfonylurea herbicides
- Rinsate
- spray onto a labelled site
- Privacy
- Runs in your browser; nothing uploaded
A few grams of the wrong herbicide can wreck the next crop
Herbicide residue clinging to a sprayer tank, its hoses, filters and nozzles does not just vanish — it carries straight into the next load. Spray a sensitive crop with a tank that last held a hormone or sulfonylurea herbicide and you can stunt or kill it from your own equipment. The fix is the triple rinse: each rinse dilutes the leftover residue by the same ratio, so three modest rinses leave only a tiny fraction — far less than one big flush using the same total water.
This tool gives the rinse water per rinse, the total rinse water and the residual percentage from your tank size, rinse ratio and number of rinses. Use it to plan how much clean water to carry, size a disposal area for the rinsate, and confirm a triple rinse drops the residual low enough before you switch to a sensitive crop. Pair it with the Spray & Tank Mix and Dilution Ratio tools for a full spray plan.
Protect the next crop
Cut carryover before spraying sensitive crops.
Carry enough water
Know the total rinse water before you head out.
Prove the triple rinse
See the residual % three rinses actually leave.
Dispose legally
Size a labelled site for the rinsate volume.
Frequently Asked Questions
Why must I clean out the sprayer tank?+
Herbicide residue left in a tank, hoses, filters and nozzles can carry over into the next load and damage a sensitive crop — even a few grams of the wrong product can stunt or kill. Cleaning out between jobs, and especially when switching from a hormone or sulfonylurea herbicide to a sensitive crop, protects yield and avoids costly spray drift-style injury from your own equipment.
What is a triple rinse and how does it work?+
A triple rinse empties the tank, then partly refills, agitates and drains it three times. Each rinse dilutes the leftover residue by the same ratio, so the residue that survives is the dilution per rinse cubed. Three modest rinses leave only a tiny fraction — far less than one big rinse using the same total water — which is why the staged method is the standard.
How is the rinse water calculated?+
Rinse water per rinse = tank size × rinse ratio (often 10–20% of tank volume). Total rinse water = rinse water per rinse × number of rinses. Residual % = (heel fraction after draining) raised to the power of the number of rinses, expressed as a percentage of the original concentration. The calculator does all three from your tank size and ratio.
What is the residual percentage?+
It is the share of the original chemical concentration still in the tank after the full cleanout. Because each rinse dilutes by the same factor, the residual falls geometrically: three 10% heels leave roughly 0.1% of the start concentration. The lower this number, the safer the tank is for the next sensitive crop.
How much water should each rinse use?+
A practical rinse uses about 10–20% of the tank's volume — enough to wet all internal surfaces and agitate well. More water per rinse lowers the heel and the residual, but three properly agitated moderate rinses beat one large flush. Always run the rinsate through the boom and nozzles, not just the tank.
Do I need a tank cleaner as well as water?+
Water alone removes most residue, but oily formulations and acidic herbicides often need a cleaning agent — ammonia, a commercial tank cleaner, or for sulfonylureas a chlorine bleach solution — added to one of the rinses and left to soak. Always follow the product label's decontamination instructions; the calculator handles the water volumes, not the chemistry.
Where do I dispose of the rinsate?+
Spray the diluted rinsate onto the original target crop or a labelled site at a rate within label limits — that is the recommended route. Never tip it down a drain, into a watercourse, or onto bare ground where it can leach. The total rinse water figure helps you plan a disposal area large enough to apply it legally.
Does the tank size or unit matter?+
Enter the tank size in whatever unit you work in — litres or gallons — and the rinse ratio as a fraction of that volume; the results come back in the same unit. The residual percentage is unit-free because it depends only on the dilution ratio and the number of rinses, not the absolute tank size.
Are the figures precise?+
They are solid planning figures. The real heel left after draining varies with tank shape, sump design, how well you agitate, and the formulation. Treat the residual % as a guide to whether a triple rinse is enough, and add a dedicated tank cleaner or an extra rinse whenever you switch to a high-value sensitive crop.