I have heard of several companies that have to replace hoses after several years and throw them away. Does anyone know of any type of companies that do this that i could search for in my area? looking to build some PVC and hose trees for structure.

Try a local well drilling company. The one nearest me throws away 300-400 feet of black plastic water pipe they pulled from wells every week. Some is in long pieces, some is already cut to structure friendly lengths.

Your local electric cooperative likely uses sch 40 red poly pipe for underground installations. It's not economical to splice short lengths, so it is scrap. You can likely find it in 2" and 4", possibly a couple of smaller sizes.