We use a variety of contractor's tubs and kiddie wading pools. We empty them regularly and refill them. We do use a dirty water sump pump to empty the bigger pools and drain the water onto our fruit trees. That is a lot easier than dumping them, but it does take a while. I'd like to make a permenant in ground pool with a liner or concrete, if I do, I plan to get a bigger/better dirty water/trash pump to empty it every few days to keep it reasonably clean.
We do empty our wading pools and store them under cover for the winter. When it's freezing I just use the contractor's tubs. I haven't found them to get brittle yet. I think too much UV does cause a lot of plastic to get brittle eventually.