When you combine two or more agricultural products — pesticides, fertilizers, adjuvants — in the same spray tank, they can react with each other before they ever reach the field. A tank mix can go wrong in two different ways: a chemical incompatibility, where the active ingredients break down or lose effectiveness when combined, or a physical incompatibility, where the formulations themselves separate, clump or curdle in the tank — regardless of whether the chemistry is fine.
A compatibility check looks up known conflicts between chemical groups and formulation types before you load the tank, so you catch a bad mix on paper instead of in a clogged nozzle or a damaged crop.
Two products with compatible active ingredients can still separate physically if their formulations don't mix well — a wettable powder and an emulsifiable concentrate, for example, behave very differently in water. That's why a real compatibility check needs both the active ingredient and the formulation code (EC, SC, WP, WG, SP, DF, FL, EW, SL) for each product.
| Formulation type | Common code |
|---|---|
| Water conditioners | — |
| Powders / granules | WP, WG, SP, DF |
| Suspension concentrates | SC, FL |
| Emulsifiable concentrates | EC, EW |
| Solubles / solutions | SL |
| Surfactants and oils | — |
Before loading a full tank, test the mix at small scale in a clear jar: add water at the same ratio you'd use in the field, add each product in the recommended fill order, waiting a few minutes between each one, then let it sit for 15–30 minutes. Clumps, layering, excessive foam or heat mean that mix shouldn't go in the tank as-is — a compatibility agent or a different order may fix it. A jar test only catches physical incompatibility; always confirm chemical and label compatibility separately.
Loading products in the wrong order is a common cause of tank mix failures even when every product is technically compatible. As a general rule: water conditioners first, then dry formulations (powders, granules), then suspension concentrates, then emulsifiable concentrates, then solubles, and surfactants or oils last. The checker above applies this order automatically once you enter your products.