On the back of the unit, on the right side as you look at the back, maybe 4-5 inches from the top there are three hose connectors (small, probably for 1/4 tubing), labeled 1,2 and 4. They are capped right now. Anyone knows what i they for? I was going to guess chemicals reclamation in separate bottles, but it may be wishful thinking. The manual doesn't seem to cover this. I'll take a picture tonight and post it if necessary.