So I have a cartridge filter setup and currently have some heavy duty algae sludge issues and had been looking at using my old solar pump to make a portable vacuum to waste option... when I noticed this extra pipe with an on off valve that goes out to the drain, got me thinking if the previous owner actually had already had a 3 way installed to vacuum to waste and just never mentioned it. Is that what this is? If so would you just plug the pump power cord into the wall directly to bypass the filter and chlorinator?