Always start with a reservoir filled with water, then add the concentrated nutrients one by one. Never mix the nutrients together in their concentrated form. This will cause nutrient "lock-out" making some minerals unavailable. If using the Elite 3-Part, it is best to begin by adding MICRO, stirring well, and then adding GROW and/or BLOOM. If using the Blue Max 2-Part, add Part A before adding Part B. After adding 1 product, always mix solution well before adding another product. If using Gold Shield, always add to the reservoir first.