Can I Put Algaecide In After Shocking? If you want to prevent algae from popping up in your pool, you may be wondering if you should add algaecide after shocking the pool. When it really comes down to it, keeping the pool clean isn’t just about owning the perfect robotic pool cleaner. Whether you are using a pool vacuum robot or a pool cleaner, the right type of treatment can make a difference when it comes to avoiding or treating the causes of algae.