Organic matter in tanks, grow beds, ponds, etc build up over time. Especially if there's not enough DO or water turn over in a system. Ponds are an excellent example of this.

In order for the bacteria to break it down quickly, it requires DO, low levels of DO are one of the more typical limiting factors in how fast sludge can be broken down into completely water solouble solutions.

So, the million dollar question is....how long does it take? IF the rate bacteria breaks it down is relative to the amount of DO....what is the ratio? And, what ratio at what amount of time?

Since I can't count bacteria, nor have a way to measure it's concentration in a given sample, I can't wrap my mind around a plausable experiment that would answer this.

We all know how to seed a system with new bacteria....and we have all read about the additives you can add to jump start your culture. BUT how do you know when you have enough? Obviously the system as a whole will balance out. But as I read, it seems that the amount of food available AND the amount of DO control the growth and reproduction rate of bacteria.
This is important to know, especially from the approach of sludge control as the bacteria that doesn't require DO breaks it down much slower. So we want the right bacteria, in the right amounts, without spending the extra money/time in over populating them just to have them die back to match the food/DO levels.

Ideas, opinions, and the like welcome. I have always trusted a system to balance..but now wonder if there may have been a more practical way.