Well I did not rent a trash pump I bought one. Glad I did because removing the muck was more time then I thought
the intake hose and all the good stuff to go with it was almost as much as the pump.... I bought a 212cc 2 inch "clear water" pump from harbor freight I was sure it was gona be a POS but it really does do a good job. I have drained it down 2x to about a a quarter of the pond and making it a soupy mess but its working. I use the discharge hose to keep moving the muck down the banks. Needless to say its working.
