Flex pipe is no good. As you stated termites will chew it and over time it can collapse.

I teach classes on pool/spa plumbing in the Northeast in my industry, and I tell my students to not use flex pipe. We only use rigid Sch 40 PVC on all our projects.

They can certainly use rigid pipe. I have used rigid on inground fiberglass spas without any problems.

Thank you! one pb said they woukd do it for an extra $2,500 but there’s a greater risk of it leaking at each connection/turn, so he had me doubting myself.

You are welcome. If the PB uses the proper primer and glue, and installed the piping properly, there will be no leaks. Pressure testing prior to backfilling is essential.

And, 2" pipe is not really BIG pipe as some PB's will claim. Most of our skimmer and main drain lines are 2.5" and 3".