I'd like some advice on the best procedure to use following a pump-out of the holding tank. I've pumped, run a few gallons of water into the tank and pumped again (twice) in order to dilute as much as possible the residue in the tank that is below the discharge elbow (about 3/4" or so). At this point should I add an enzyme additive to the tank? Wait until its first use? Thanks very much for advice.