@janovr, Being screened in means that you are still getting fresh outdoor air around your daughter's pool, so it is not considered an indoor pool. It gets hot in Florida and can make outdoor pool water warm. Mac likes warm water. Being a private pool lessens the chance of it having a lot of mac in it. NIH did a study on contaminated pools and found that most indoor or outdoor pools had some level of mac in them. The pools that tend to have the most mac in them are high traffic public pools & indoor pools. Mac tends to colonize in warm pool water. That is why the indoor pools tend to have a higher count. I rarely get into pools. When I do, it is for a quick fanny dunk to cool off. I only do that if the water looks really clean and clear and I keep my head high out of the water. Some members on our site are very ill and are having a tough time battling their mac. In that instance, I would avoid a pool like the plague.