Thanks for response.
The pond those guys worked on was my 36 year old swimming pond. My back pond is the one that had the coontail.
I did have someone from Ohio extension offices verify. Believe me, I pulled probably a thousand pounds of the stuff. A lot anyway!
Now on the subject of depth. Depends if you go thru the muck to solid base. If to the muck maybe not. Should I only figure to the muck layer?