I decided on a liner.

I initially wanted to use EPDM, because most sources say it’s the stronger and more durable option when compared to PVC.

However, I recently found out that you cannot simply weld EPDM using heat. But I really want to try welding liner to avoid unsightly flaps and folds in the pond. And it goes without saying that I’m too cheap for specifically developed double-sided tapes and primers that are used to bond EPDM sheets.

I luckily found a solution: 4everflex pond liners. A combination of the best qualities of EPDM (see above) and PVC (you can weld it) for a price comparable to EPDM.

Ideally, I’d buy a small sheet and try welding that before committing, but I don’t have time for that shit so I’m going all in and trusting my – not yet developed – welding skills. Let’s order. 😀