Also, Whoop. The agitation nozzles at the bottom of the tank often plug up with debris--particularly if you use pendimethalin. Very hard on the pump. No restriction allowed here. Pull them out and clean them up good. It is best to replace these with agitation nozzles that can pass any pieces of debris that get by the filter. Try using agitation-booster type nozzles. (With BIG openings). And put three or four all aimed in the same direction. They will cause your liquid solution to swirl, giving you better agitation. I tried to find proper nozzles on Rittenhouse--but couldn't find them--maybe Bob Rittenhouse can help.