1 would be storage and developing adequate pressure.
I have 2 systems, 1 is a parts washer that I use solvent in to clean squeegees, floodbars and spatulas. The other is a waterbased only tank that I use for reclaiming, developing and cleaning water based products like emulsion.
This is what I would recommend. I personally don't see how a system with no drain, that recirculated used water would be effective. Especially given the broad range of chemicals that are used in this industry.