This will depend on the extent of algae infestation in your pool. The robot will have no problem with a few algae and will actually scrub them off the pool surfaces. But a pool with severe algae attack will have very slimy and slippery surfaces which will tremendously affect the ability of the robot to move and clean effectively. In this case, you’ll need a shock chlorination treatment. And please do not introduce the robot to your pool during the treatment as chlorine can damage some parts of the machine.