If your pool is already painted, you will need to know the existing paint type before applying any new paint as not all paints are compatible. This can be determined by sending a sample to Ramuc (or other paint manufacturer) if the paint type is unknown. There are also a few tests you can try. Take a 1 inch paint chip, immerse it in denatured alcohol. If the chip dissolves, it is a water-based acrylic. If it doesn't dissolve, immerse a new chip in 75% mineral spirits and 25% Xylol, wait 30 seconds and rub the chip between your thumb and forefinger. If it dissolves, the paint is a synthetic rubber-base coating. If not, try immersing one last chip in 100% Xylol. If it dissolves, the paint type is chlorinated rubber; if it does not, it is an epoxy.