I got my pipe free as well and they ranged from 14-24 inch od. I bought 8in pipe 20 ft i think was the length and they were close to 140 each with my disabled vet discount. The bigger ones gotta cost way more than that 8in. I put in my pipe b4 the pond filled with water, used a bachhoe to dig each hole then poured an 80lb bag of concrete in each one. You could do the same. As long as you set it upright is should stay if you use a tire at one end. just screw the tire 2 the pvc and fill with concrete mix or chunks of broken used concrete. If you want, make some 4-5 ft tall and fill them totally with rock/rubble. it would probably make a great crawfish hide. I like the very large diameter white pipe in the center of the first pic, that one would work very well.
