While quick connect fittings may work in some cases, we do not recommend the use of quick connect fittings. Most, but not all, quick connect fittings are designed for air pressure and not vacuum. The fittings rely on the internal pressure to actually seal the fitting itself. We have seen some quick connect fittings that would hold a vacuum but a lot depends on the design and how it was manufactured internally. Unless the quick connect fitting is actually rated for vacuum operations, we recommend against it. The other drawback is that quick connect fittings usually cost about four times as much as other reliable methods. Availability can also be an issue if you develop a leak, You do not want to have to wait a week to receive a special quick connect fitting. We recommend using tried and true vacuum connections that use standard parts you can find at your local home center. That way, if you have a problem or need to change the plumbing connections for some reason, it is easily done. Once your system is setup the way you want it . . why do you need quick connect fittings? They are just not necessary in our opinion.