Pools can seemingly turn green overnight, but believe it or not, algae has been present in the pool for a while. Algae starts life off as a transparent growth. It is invisible to the naked eye but you can usually tell by feeling a slippery and slimey surface. When the water becomes green, algae has a very strong foothold on surviving in your pool. Algae growth can also be accelerated by the presence of nitrogen found during heavy rain storms or lightning storms. Overnight greenness is usually a coincidence or perhaps the water hasn’t been consciously noticed for a day or two. It’s OK, we can help with the treatment of algae, let us know how bad it is with a photo of the pool.