Converting water feature to pool

[LilaFowler]

Hello:

We recently purchased a house with a pond/water feature in the backyard. It's probably about 15 x 20 feet and about 2-2.5 feet deep and irregularly shaped, with a small waterfall. There is a filter and pump and the previous owner chlorinated the pond to keep it clear, which we have continued to do per his instructions. It's lined with a heavy plastic liner.

At some point, we would like to convert this into a small pool. What would we need to consider to make such a conversion? I am thinking we would need to line the pool with something more durable and possibly replace the pump and filter as I don't know how much of a difference there would be between the pump/filter system for a pond vs. the pump/filter system for a pool that people will be swimming in. If anyone can give any insight as to other things I may not be thinking of, that would be great.

Thank you!