5/8 or 3/4 barb
Most of the posts concerning DIY reactors specify using 5/8 barbs because the common hose is 5/8 ID. There are numerous comments about the difficulty of finding these - maybe the reason is that we really want 3/4?
I measured some spare parts I had left over from a canister purchase. The spray bar was 5/8 OD and fit snuggly in the hose. There was a barbed connector, and it measures 3/4 to the outside of the barb. The inside of the barb was 5/8. I then went to Home Depot and looked at what they had. The brass barbs that were labeled 5/8 went right into the hose with no resistance. Those labeled 3/4 seemed like you could muscle the hose on. When I hooked up the canisters I remember the assembly being a PITA.
So, should we be buying those marked 3/4?