back-flushing a bog: how to do?

[addy1]

I have not seen a snake in the bog. Heron, frogs, hawk, fry, tads, bugs, who knows what is hiding in the plants. Get it built I could send you a bunch of starts in the spring of bog plants

 

[Dave's pond Indiana]

In reference to build up in a bog. Isn't everything that goes into the bog bio-degradable? If it is that would account for the lack of build up in the bog. I think the size of the bog compared to the volume of water going through it would account for the amount of build up. It seems to me that the larger the bog the less build up you should have.