Filling your EZ-FLO System is very easy and takes only a minute or two. We recommend using a heavy duty funnel (Part# EZ-FNLSC) that is stable when placed into the fill throat of the unit. This allows you to pour the water soluble fertilizer directly into the tank and then dissolve it with water. No pre-mixing is required since the units are designed with an agitation fitting to keep the solution in suspension once the unit has been filled and topped off.