Phuket has a nice warm climate. Everyone is looking for relieve in the water. Swimming in sea gives a special feeling. Phuket coast has April thru October a dangerous under current. Better listen to the beautiful bay watchers. In the swimmingpool there is no current. No red flags there BUT in this tropical climate it is not easy to keep your swimming pool clean. The use of chemicals like chlorine is good to loose algae but it neither healthy for our body. Chemicals in a swimmingpool has to be monitored daily and since most pool boys make no plan your pool turns into a chemical bath with continuous chemical reactions. Chlorine to high? adding Acid resulting in Ph to high solved by adding to much sodium. Probably it is healthier and more relaxed to take a saltwater computer chlorinator which gives you the sense of swimming in sea as well.