I want to upgrade from a gI to gIII on a budget and had a couple quick questions(leaving the center system alone):

Could I use one reversible pump with a dedicated thru-hull, tee off after the pump and run hoses to both rear bags, putting a valve just before each bag so I can close one and fill/drain the other?

Would I need to vent the bags or not because of the reversible pump?

I am correct in that with a reverible pump you only need one hose going to each bag and it will push water back out the thru hull?

I've been doing alot of research on others modifications and found jesters how to thread very helpful!

Thanks for any help!