I know this has been done by many members, and in a much nicer way. But I finally built my first holding cage yesterday. I used CPVC pipe and fittings, and 1/2 inch plastic hardware mesh, and UV resistant zip ties. I designed it to stick up out of the water about 18 inches, to make easier to lift out AND prevent ricochets when tossing in a fish. The dimensions are 51" tall by ~ 3 feet (in an oval shape).
3/4 inch CPVC tubing was about $50 for 100 foot roll; 3/4 inch CPVC rigid pipe was $4.50/ten foot piece. CPVC fittings are ~ 79-99 cents each. Bag of 100 UV resistant black zip ties was ~ $5 ( I used one full bag plus 10-15 from second bag). 1/2 plastic hardware mesh (for 3' tall by 15 feet long roll) was ~ $15. Assembly time was ~ 1.5 hrs, but I'm sure I could be more efficient the second time.










"Politics": derived from 'poly' meaning many, and 'tics' meaning 'blood sucking parasites'.