Here is a photo of one of my PVC Mineral
Feeders.  I also use them for baking soda.
(click here for my comments on using Sodium Bicarbonate)

This one is made with 4" PVC piping.  There
is a short 4" pipe on the bottom so I could
connect a cap.  The cap on top is not
screwed on.  This one is about two and a
half feet high and holds about ten pounds of
mineral.  I've had no problem with
the goats leaving presents and it does
not get yucky.  

The goats love it and so do I!
PVC Mineral Feeder
Sleepy Z Goat Farm
PVC Mineral Feeder

Hastings, Michigan
Call or Text:  (269) 838-4564
Sleepy Z Farm