Repainting the interior of a swimming pool yourself can save you money when done correctly. But you should consider several things before making a final decision whether to do it yourself or hire a professional. Time of year, physical limitations, safety and overall condition of the pool need to be factored in. A fresh coat of paint will not only make the pool look better, it will reduce algae growth and help with cleaning.
Determine the current coating of your pool and how smooth or rough it is. Pool coatings can include acrylic, epoxy or rubber-based paints. Uncoated pools will have unpainted surfaces such as concrete, fiberglass or plaster. If you are unsure, consult the dealer where you will be buying your paint.
Calculate the size of your pool. According to the pool and spa informational website askalanaquestion.com, three calculations will be helpful. For rectangular or freeform shapes multiply length times width times 1.6 to get the square feet of interior surface. If the pool is oval or lazy-L-shaped use length times width times 1.65 to determine the square footage. Use length times width times 1.55 for Roman Style shapes.
Buy the appropriate amount of paint and supplies using this information. This can be done online or at a local retailer.
Empty the pool of water. Remove all leaves and debris. Use a shop vacuum to get that last bit of water your pump can't. Prepare the surface by cleaning it according to the instructions which come with your paint. This may include a thorough washing using tri-sodium phosphate (not detergent type cleaners) and depending on the type of surface you are prepping, possibly a mixture of muriatic acid and water. These cleaners will also need to be emptied out of the pool, so check with local ordinances prior to disposal.
Begin painting with the deep end walls. Roll the paint just as you would the wall of a house. Work your way down to the center and continue into the shallow end. The initial state of the surface will indicate if a second coat is needed. Consult the label on the paint to determine cure time before refilling the pool.