I finally decided to address the problems as best I could and wish my fish the best--- my best turned out to be good enough.
This particular pump had more flow than the one through the sculptured fish mouth. I got it for another project. Its a water pump for land yachts and runs off of +12 volts. You can see my add on cable so I could run in out of our car's cigarette lighter socket. I fixed up the pump in / out connectors to work with our lawn hoses. I mounted it on a board I never did use for a cabinet drawer front (hence its pretty edge). My pond is more of a pit than a street pot hole and holds a bit over 300 gallons. I started at 9am and was completely done just as dark encrouched. I never needed any help, though I wouldn't have rejected it if offered. My friends are too smart.
I pumped the water into a kiddle pool that I bought brand new from Target for $8.99 + tax. Though I worried about the plasticizers leaching into the water and harming my 2 goldfish (2 charmers 3 years old now that my wife rescued from being bait at 25 cents each from the pet store's "feeder fish" tank). I didn't do anything about it except know it would only be for 4 or 5 hours.
Click on this small, cluttered picture to get a 640 x 480 version. You will have to ignore that aquarium in the foreground (a project I don't want to talk about). You can see the pump just to the left, and behind it is the kiddie pool, full of water, and 2 fish hiding under the bush and at the bottom. I kind of did worry that a predator would swoop down and go fishing, but that didn't happen. I found that I had to use my trash cans, buckets and other supports around the edges of the kiddie pool in order for it to hold as much water as possible. It always seemed to want to pour out the downhill slant.
As the water level in the pond got low, I used a net to transfer the fish to the kiddle pool. The suction hose had to be supported in varying ways to keep it from getting real close to the muck or it would quickly quit sucking at all. That's what the rock on the upside down planter box is all about. Then into the "water" with shoes and my bucket. I spent the next several hours coaxing the muck into the bucket, lifting it to the pond edge, climbing out, picking the bucket up, walking to the nearby leaf compost area behind that tree in the next picture, dumping it and retracing my steps. Repeat. It was exhausting.
I used a regular hose and city water to clean the last bit from the bottom and sides. I mostly used my hands to knock crud down into the bottom. The resulting water in the bottom I just bailed to the garden adjacent to the pond. Then I simultaneously pumped water back into the pond and ran the hose, too. (I have 3 hoses.) The fish went back in. Rehooked up the regular "mighty pump" and quit.
I left a mess around the pond which consisted of rocks and odd pieces that have fallen in there over the years. I also left the emptied kiddie pool; all to be dealt with on the morrow.
[Note: I did the mucking in March of 2006. Only took a year to get this report up on the web. The same two fish are as happy as can be. I didn't get sick, the muck composted without smelling.]