Randy H. , BM and ML :

Good topic. Good advice. Couple of points. Get the water tested as BM says. Also get soil samples from around pond bottom and have your county agent have them tested for pond suitability. Costs $ 6 here and you get a detailed report on what you should do. The lack of adequate alkalinity {lime} is a limiting factor to plant growth in the garden and pond. If you have lots of nutrients but no alkalinity and add lime you may get a plant explosion of all kinds. Know the situation before you act. As ML has warned many times get the plants under control before you do anything that might make them go out of control. Aeration may well put more nutrients in the water column just waiting on lime which will be circulated to bottom where FA will use it as will plankton. Will the plankton be quick enough to shade out FA ? I would not bet on that given the difficulty on dealing with FA. Ditto pondweed { those that I know about} except you can't shade it out with plankton bloom . ewest