For those of you with an Elma or similar unit, how is the design in this area. Maybe, like a household sink, the water outlet should be in the center of the tank?@Slaw - Which Elmasonic machine do you use? On the Elma P120h there are two rows of three transducers organized on the tank bottom. I suspect that placing a drain in the center of the tank would disrupt that layout and possibly impact dispersion of the cavitation action.-
One idea is to run your pump/filter for 10-15 minutes prior to starting a cleaning session or alternatively do that every week whether you clean or not. Another is to use a TDS meter to gauge water/solution purity.
I don't know the layout of your setup. Presumably you have the pump prior to the filter(s). Not questioning your approach, I'm a bit surprised at the need for two filters. Which cannisters do you use? I switched to a .35 micron filter. Have not seen the condition you describe.