Pond Boss Forums AERATION Systems questions Can I aerate just part of my pond?

Since you are legally not supposed to use any herbicides and tilapia are out of the question in your state then about the only feasible alternative that I think you have is manual removal and this for a 2 ac or even 0.5 ac is an unreasonable amount of work. I do not see how aeration would prevent enough reduction of nutrients that it would make a noticeable difference in reducing filamentous algae(FA). I will assume that it is one of the nutrient loving filamentous species that is getting its nutrients from the leaching from the sediments; probably either Cladophora, Oedogonium or Mougeotia however it could be one of the other cool water loving genera such as Spirogyra. One would only know which one by looking at it with a microscope.

FA almost always starts growth on the bottom where it begins growth by attaching with specialized holdfast cells. The filament elongates until it forms long strands that eventually break loose and the strand mass floats around on the surface until usually a strong rain or strong wind breaks it up and sends the floating stuff to the bottom where it begins decomposition. A strong powerful spray or wake from a motor boat can also break up floating FA.

One other option that I see that you have is to use a very environmentally harmless chemical, even to trout, is chemically called sodium carbonate peroxyhydrate which is granular hydrogen peroxide basically strong H2O2 that is dried down on washing soda (a type of baking soda). H2O2 releases oxygen and degrades into water H2O. This will not harm trout and most all aquatic animals. Common trade names for this chemical are Phycomycin and Green Clean Pro (having the Pro part is important). To use this chemical best it has to be used broadcast onto the growth when the algae is first starting to grow as 1"-3" tall fussy stuff. Taller than 3" it takes an unreasonable amount of peroxyhydrate to get the algae knocked back. So to use it effectively one has to be very proactive in its use and disperse it when the algae is in early growth stages. It does not work as well as copper based algaecides but it is environmentally much safer.