In the near future I will begin injecting sodium aluminate to treat phosphorus in an aeration tank as a replacement for previous use of ferric chloride. As a result, I am looking for experience and input on any drawbacks to its use (for example, problems with crystallization in the pipes, high viscosity, precipitates, etc.) as well as best practices to ensure maximum effectiveness (for example, regular purging of the pipes, the most suitable type of metering pump, etc.).
We use it a lot in both water treatment and wastewater treatment. It can be very effective in P removal. I think of it like caustic soda where the freezing point is high. Make sure your lines are insulated. Check the tank regularly as the product tends to have drop out or crystallization which can cause many headaches.