[dhitchco]

Elsewhere in this forum was a discussion about using plastic tie-wraps as the corner connectors especially for the goals; not the movable tetras.

Just drill holes through the ends of the goal pieces, thread a long nylon tie-wrap strap but leave them loose. Once the entire goal is put together, you can "cinch-up" the nylon tie wraps to make the structure rigid.

That way, you save the cost of the PVC end caps (which seem to be in short supply) plus you have less labor to assemble and a lot less time to dis-assemble when done.