How long to replace water from infllatable mini pool and what should I do to sustain good water?

The size of the inflatable mini pool 72" in diameter and 20" in height.|||if its out in the open air you will need to change it every 2-4 days depending on how hot and humid it is. the water will end up being a breeding ground for bugs. aside from getting a pump you can cover the pool with plastic whenever its not in use. that should buy you a few more days before changing the water.|||I would replace it often and you need a pump to sustain good water.