wingsfan -- I have not used microbes but I hear testimony from numerous pondowners that have had good experiences with them and they keep buying them, especially when they find a brand or blend that does the job they are seeking.
Microbe blends can be quite different in what they accomplish. If I had a particular problem that microbes would help with I would not hesitate to try them after doing some intensive homework.
I do not currently have anything that I perceive as a problem with my ponds. I use no chemicals and maintain a natural biological balance that incorporates complete bottom aeration to produce good oxygen levels at all depths.
