I stock a lot of fittings. They make a lot of thread sizes that fit the 1/2" tubing so you don't need to use reducers. There are a lot of other manufacturers besides Qest making fittings now like SeaTech snap-in fittings, Flair-it and others. The Flair-it as a very easy type to use, as is the SeaTech if you can find them.
Solar Tech Energy Systems, Inc.
Victron Solar Components and Inverters, Zamp Solar Panels, LiFeBlue and Battle Born Lithium Batteries, Lifeline AGM Batteries