Black algae generally penetrate porous pool surfaces like concrete and gunite. Once these . CLEAN FILTER - If black algae are in your pool, it's also in your filter. If you have a sand or DE I should have done a before and after with photos. Would like to clean up whatever this is, re-grout and reapply the tiles . Here are pictures of a molded Bathroom before and after mike . area, then use a chlorine tablet and rub over black algae; it can also be broken-up to reach other areas. May 8, 2017 - . to kill it?: How To Clean Algae From Swimming Pool Tile Grout - . It's growing in the shaded area of this picture: Pool.jpg. Thanks TFP! Information about algae in pools. How to remove or correct the conditions that have caused algae to grow in your pool, and steps on algae prevention. This is why it is important to remove and prevent swimming pool algae. algae growing along coping surfaces, on tile grout, and along pool stairs and steps. You will usually find black algae clinging to your pool walls or steps in very shady spots. . With that said, always wash your bathing suits after swimming. It's just . As the images show, we are able to successfully remove this staining from almost . products to remove what they thought was green algae from the pool tiles. There are ways to treat your pool and rid it of black algae, but prevention is always the . On a weekly or bi-weekly basis, shock your pool to remove chloramines .