Sue,

You are exactly right...everyone is selling bacteria. Why? The MAIN reason: their customers "feel good" about applying something natural in their ponds. Also, it is a carry over product from ornamental backyard water gardens (talk about a market of rip-offs!) that is now available to those with larger bodies of water.

You are correct, the BT strains doing the majority of the work in these products are naturally occurring in most ponds. We supplement using these microbe products because the naturally occurring microbes can't keep pace with the nutrient loading that takes place around our man-made ponds/lakes.

Your question: "Why do bacteria levels go back down to normal levels so quickly after a treatment. If there is an unlimited food source and plenty of oxygen to go around, why do they die off so quickly and need to be added again?"

I'm not a microbiologist in any form, but my understanding is bacteria levels fluctuate due to dilution (water exchange from a rain-event, etc.) and the natural balance and control within the pond itself, i.e. components within the pond's ecosystem will not allow the bacteria to reach a harmful concentration.

Yes, by adding mechanical aeration, we do see a reduction in all the things you mentioned. This aeration does provide a better environment in which naturally occurring microbes can process nutrients. Why add more? Because you can. I agree that "large amounts" are not necessary, but in the scope of things, by supplementing with manufactured bacteria, I wouldn't necessarily say it is "large amounts."

Microbe treatments can be expensive depending on the pond size and location. Large ponds are sometimes cost prohibitive and not worth the treatment. Other smaller ponds are also cost prohibitive because the amount of water exchange that takes place on a regular basis (on-stream ponds). However, your client is ultimately the one that decides what is expensive and what is not.

I get asked the same questions you do regarding the products to help solve their water quality problems. It's not the magic bullet to all water quality issues, but it is definitely a tool that can be utilized from our pond management toolbox in the appropriate situation.

BTW...speaking of "everyone selling bacteria". I just noticed a few months ago that one of your competitors out of Kiel, Wisconsin (I won't mention the name) has introduced several new, here we go again, "proprietary" blends and many different applications methods for their new microbe lines. In my opinion, they don't have anything "new" on the market as far as bacillus strains; they are just marketing new "gimmicks" on ways to apply their products.