I strongly recommend Mar Azul pool. I have a fairly new pool and my previous company (Penguin Pool) was not doing a very good job. I noticed a yellow ring around the bottom-edge in the deep area of the pool. They could not figure out how to correct the problem. I asked Mar Azul pool to evaluate the problem and provide me with a solution that would remove the yellow ring around the edge. Saul immediately recognized the cause of the problem, began treatment, and removed the yellow ring within 3 weeks. Ever since he took over the maintenance my pool looks amazingly clear. He has knowledge, very responsible, punctual, provides great work quality, and $$ prices are very reasonable.