We have an approx 500 gal plastic(?) preformed pond partially above ground. We are second owners to the home, and did not install the pond.

The guy we bought the house from did things his "own way", which we have discovered the hard way during our current remodel. Hence, I'm not sure the pond is set up the correct way.

Our immediate problem is that there is an overflow spout that has come uncaulked and is causing a massive water loss.

I could probably fix it without draining the pond, but I am considering a full drain so I can set it up the right way, including setting up a filter system! Because of no filter it really needs a good cleaning too.

Currently he has rigged a pump that's attached to an old-fashioned water hand pump, which pours water into a faux barrel which spills into the pond, so water is moving but I assume it should have some kind of filter??

My questions:

The fish, approx 20 fancy goldfish a few maybe 10", most are 4-6":

Do I move them to a kiddie pool or pools? We have a shop we can put the pools in to keep them safe from kritters.

Should I use some of the pond water that's left to fill the pools?

How long can they safely stay in the pools?

Any other considerations?