What is the order in which materials should be added to a tank?

• A. Wettable powders/dry products
• B. WALES
• C. Liquids
• D. Emulsifiable concentrates

Answer: (B)

The main idea is to use the WALES sequence when filling a spray tank. This order helps each component dissolve or disperse properly and prevents compatibility problems, clumping, or residues.

Start with water in the tank and turn on agitation. Then add additives such as compatibility agents or surfactants so they can mix evenly with the rest of the mixture. Next come liquids, which can dilute and carry active ingredients and should disperse smoothly in the water. After that, introduce emulsifiable concentrates so they emulsify into the solution rather than forming separate layers or sticky clumps. Finally, if dry or wettable powders are used, add them last while continuing to agitate so they stay suspended rather than settling or lumping.

This sequence minimizes formation of clumps, reduces incompatibilities, and promotes a uniform, stable spray. Always follow the label, as some products may require a different order.