By Melody Shaw, Narrow Gate Nigerian Dwarf
I chose the 4" fittings and they have worked perfectly for my Nigerian Dwarf herd, but if you have larger goats I'd recommend bumping that up to 6".
Each piece fits snugly into the other so the only piece needing to be glued is the (half) cap at the feeding end. Use PVC cement.
The photo at the bottom left shows how I use an old hose to secure them to the bottom 2" x 8". Not shown in the two photos is the 6" hose clamp I have put around each feeder's neck and secured to the wall (for added stability). Photo in the middle how I have used a bungee cord to secure it. The photo on the right is a gradient feeder.
I recommend placing them at a height that is 2" higher than the rump of the goats you are using them with. This (along with the small feed opening) prevents poop from getting into your mineral.
Each 4" feeder holds 2½ quarts of mineral.