Due to the surprisingly high cost, including shipping, of large water tanks (say, 100 gallons), I'm evaluating the possibility of creating one via 3d printing. (The pieces would of course have to be printed in chunks and fused together in a durable and watertight fashion-- I'm assuming for now that this can be done. It seems like a separate question, but feel free to address it in the comments.)
The question at hand is: is there any filament suitable for the task? The container needs to be able to sit out in the sun year-round without becoming nonfunctional.
The resources I've been reading (linked below) are suggesting PLA filament for small kitchenware items, but from what I've heard, that tends to degrade pretty quickly in the sun.
Are any filaments suitable for this?