Slip on a pair of rubber gloves and safety goggles. Create a mixture of 1/4 cup chlorine bleach and 1 gallon warm water. Stir the ingredients until they are well mixed.
Dip a plastic scrub brush into the bleach mixture and work it into the algae. Continue to scrub the algae until it is completely gone. If this isn’t enough to remove the algae, move onto the next step.
Add an additional 1/4 cup bleach to the existing mixture. Stir the ingredients and wet the plastic scrub brush’s bristles.
Work the bleach mixture into the aluminum pool cage. Continue to apply the mixture until the algae is eliminated.
Dampen a kitchen sponge with plain water and wipe down the painted aluminum cage.