Tank Mix Compatibility Calculator

Every additional formulation multiplies the number of possible product-to-product interactions in the tank, not just the number of products, so the calculator subtracts 8 points for each product past three (and another 10 once you pass five) as a proxy for that growing combinatorial risk. Two products that are each fine on their own can still destabilize a third when all three are present, which a pairwise check alone wouldn't catch.

EC formulations rely on emulsifiers to keep oil-based actives suspended in water, and the surfactants in a WP or WDG can strip that emulsion apart, causing the mix to separate, curdle, or clog nozzles — the single most common real-world tank-mix failure. That's why this pairing costs 25 points on its own, the largest individual penalty in the model.

A score of 50-79 (Moderate) means the calculator sees enough contributing factors — extra products, harder water, off-range pH, or cold water — that a physical jar test is strongly recommended before you commit a full tank. Below 50 (High) means don't load the sprayer at all until you've run that jar test and confirmed the mix holds up, since the penalties driving a score that low usually stack from more than one source at once.

Calcium and magnesium ions in hard water can bind to certain herbicide actives (glyphosate is the classic example) and precipitate them out of solution before they ever reach the plant, reducing efficacy independent of any mixing-order or emulsion problem. A water conditioner like ammonium sulfate ties up those ions first, which is why the flag appears at a lower hardness threshold (200 ppm) than the harder penalty band (250-500+ ppm) used in the score itself.