How to Paint a Mural in your Pool
In recent years we saw a trend of decorated swimming pools. Drawing inspirations from ancient Greek and Roman bathhouses with mosaic motives on the floors, the new technique of using many small colored tiles to the 3-D effect has made some truly stunning creations. However, if you already have a pool that looks plain and dull, there is an easy way to make it attractive – by painting a mural in it. This DIY project can give you many hours of fun and joy.
Your suburban backyard pool will hardly ever reach the splendor of these pool marvels, but you can make it more interesting by painting a statement mural. There are many ideas you can draw your inspiration from, like a demanding coral reef theme, with tropical fish and abundance of dancing colors. Another effect that needs some skill to complete is a deep blue hole. By starting with light blue near the upper walls, the blue gradient recedes into dark blue in the deeper areas and the bottom. It creates the illusion of depth. Some of simpler and easier to do shapes include ever popular sea turtles and dolphins, classic mermaids, shellfish or even brands or your favorite company logos, including football club emblems.
Image Sources: 
What Paint to Use
When choosing a swimming pool paint it is important to use the type that is already used on your pool walls – epoxy, acrylic, or rubber-based. It helps to know that a pool that has been painted with epoxy cannot take rubber-based paint or the other way round. Acrylic can however, be used on any surface with no problems.
Preparation for Painting
Once you have drained the pool and opened the hydrostatic plugs, inspect the walls for any cracks or leaks. There are pool repair products like CementPatch or E-Z Patch 1. When that is done, the pool has to be prepared for painting. You will need a bucket, an acid brush and a long hose. First, use TriSodium Phosphate to remove any oils, grease or dirt from the walls and bottom. Use a mixture of TSP and warm water, pouring it and scrubbing along the surfaces, especially near drain areas and steps. Before moving to the next step, rinse all the surface with water from the hose.
The next step is acid washing, which creates tiny, porous holes on the surfaces that help the paint settle in smoothly. Use a mixture of 1 part muriatic acid and 1 part water. Pour it on small areas and use the acid brush to move the mixture around. Once done, rinse everything with the plenty of water. Be sure to use protective clothing, eye protection and a respirator that blocks muriatic acid fumes.
The Painting Phase
Begin by priming the surfaces, for smoother painting and better adhesion. Depending on the type of paint, you need to use either Epoxy Primer or Gunite Primer. Painter’s tape will help you keep anything you don’t want painted protected. Either a spray painter or low nap paint roller will work. You will also need a smaller hand brush for tight corners. If you have decided what mural you want to paint, make a paper sketch and color it how it should be in the pool. Paint the background of the mural area with a coat of white paint, allowing it to dry for 1-2 hours before you start painting the mural.
NOTE: If the mural is complicated, and involves several days of work, it helps to sand base layer surface slightly before you paint each area.
Your pool mural will definitely improve the looks of your backyard, either with water in it or empty. These ideas can be developed into project for the whole family, or if you are single, for the whole bunch of friends.