Do it RIGHT, THE FIRST TIME. These are the directions from the pool store Pro-Source Caribe, in front of Ocean Village, Sosua;
Steps for cleaning and painting a pool
Remove all of the loose and flaking paint.
Remove main drain cover and injectors. Remove lights from niches and place them on the pool deck.
Repair and patch any rough surfaces. A smooth surface yields the best paint job. DO NOT polish the surface with a power grinder.
Clean the pool with T.S.P. or strong soap, with a scrub brush, to remove body oils. Acid treat the concrete/pool surface with a mix of acid & water 50-50 and rinse well, using a brush.
Dry in the sun for 3 to 4 days. Test dryness by taping a 16” x 16” plastic sheet to the bottom of the pool for half a hour, in the sun, and check for moisture on the bottom of the plastic. If dry, proceed to next step.
For patches and new cement, thin the epoxy with 15% to 20% of thinner and paint the raw surfaces. This acts as a primer/sealer for the next coat of paint. We recommend TROPICAL brand industrial epoxy and follow the mixing directions on the can. Also, buy the epoxy at a large ferreteria like Ochoa or Americana that sells large volumes of paint because epoxy has a short shelf life. We highly suggest using White or Sand color in pools with with a Blue tile line.
Cut in (detail) the tile edges and around fittings first, and then use a good lambskin 9” roller, with ?” nap. Remember, the first coat will use much more paint than subsequent coats.
Next day, paint the first full coat of Epoxy in late afternoon to avoid the sun from drying the wet epoxy too fast and creating small bubbles. *** For slip resistant steps and stairs, immediately after painting the first coat of epoxy, sprinkle a fine coat of dry pool sand over the steps.
Next day, and within 24 hours, (before the paint is fully cured) apply the second full coat of epoxy in the late afternoon as to avoid the sun from drying too fast and creating small bubbles.
Let the pool dry for 4 days in the sun before filling. Filling sooner will prevent the epoxy from curing to its full hardness and prematurely pealing. If rain occurs, drain and dry the pool in order that the epoxy fully cures.
Once the pool is full and operating, maintain normal chlorine and water balance.
Put chlorine in the skimmer, not in the pool or on the new paint.