jspann1953, we know phosphates are looked upon as algae food. For most pools, an elevated phosphate level simply means that there is food available, but if the algae is not present there's nothing to consume it, so it doesn't matter. Most TFP owners are probably oblivious of their phosphate level for that reason. Joe asks the question of scrubbing and circulation because even if the water has a consistent FC level above the TFP minimum, an organic biofilm can develop in some areas of the pool contributing to algae. Of course there are other factors that can contribute to the development of algae, but every pool is different.
While TFP maintains the concept that phosphates are not a primary contributor to algae development, there are some unusual cases across the country where a pool owner may need to consider phosphate management. Again,
this is not common, and most pool owners do not need to go down that road. In most TFP scenarios, algae simply showed itself from something overlooked or unforeseen (storms, missed FC dosing, testing, hidden algae location, etc).
As a pool owner you have every right to pursue phosphate management if you wish. Just remember it doesn't remove algae. Once algae is in, you must perform a
SLAM Process. If you do decide to explore phosphate management, we recommend you obtain your own phosphate test kit. Just like other tests performed at the local pool store, they can be flawed, so it's always best to test the water on your own. Also, we recommend avoiding the local store's over-the-counter phosphate products as most of them are overpriced at ($60 per bottle) and do little to control phosphates. Instead, consider purchasing a commercial-grade product from SeaKlear and Orenda. Those seem to be much more reliable and should last a very long time.
Hope that helps.