I know people say shade helps, but in ky experience, algae grows because of what’s IN the water. Sun may speed the growth or green it up, but it’s not a direct cause. When my kids we little I’d put the kiddie pool in the shade - two or three days was all it took for the algae to start. Replacing some of the water won’t reduce algae at all - it will just force your pond to keep trying to balance.
If this is to be a swim pond, you still need plants. Create an “in and out” spot and plants go everywhere else. If you need a bit more help, try some sodium percarbonate every now and then - perfectly safe and it will help control the algae. Or hydrogen peroxide - same function. Cheap, easy and safe.