Like many pond matters it is a question of balance. WRT the article above it repeats a misconception as to recreational ponds , that is if you want fish. Removing all the P by bonding with Alum is not a good idea for the food chain. No P - no plankton (bottom of the food chain). There is usually one big difference between fish ponds and waste water treatment ponds - one is good for fishing the other not.
I like fish so IMO alum is not the way to treat FA. Alum when used correctly is a good tool to treat clay turbidity.
I agree 100% with you ewest!
My use of alum has been due to EXTREME clay turbidity which prevented anything BUT, FA from growing. After 3 years since building the pond, other than FA growing, the ONLY plant in the pond was a single Arrow Arum that grew from the base of an exposed rootball when the pond was lowered 12 feet for some Dam reworking.
As I said, I agree with you. I don't want a swimming-pool-pond, but with no light penetration, it HAD to be cleared to have a chance to grow anything other than FA.
