spicey
Hi Most goldfish I believe are coldwater fish, but I don't know if you had some delicate variety.Koi were bred for ponds.I don't have a lot experience w/ keeping goldfish alive, haveing only tried w/ indoor fish when my kids were little, but I,ve had excellant results w/ koi in a very small outdoor pond for the last four years.
Its a pre-formed plastic 100 gallon type I bought @ loews or home depot. I bought an agricultural bucket de freezer the kind you put in a water bucket for cows at the feed store, and this year I found a fully submersible aquarium heater at petsmart. I bought one that was small enough to have the water line covered even if the pond evaporated a little. I placed it in the center inside a vase covered w/ gravel or you can attach it to the graveled filled vase on the outside w/ the little rubber suction cups. I don't like it that way because inevitable the little cups pop off and get lost especially when cleaning your pond. These just keep the pond from freezing and I winter the fish very well in it. They don't eat much in very cold weather but if you get a mild spell feed them an all weather food or food formullated for cold water.Wrong food can make them sick. My pond is on the outside of my carport where I have access to electric, but I'm considering putting a a special outdoor plug adjacent. You will want to make sure you follow directions for grounding the agricultural de-freezer.When you have a really small pond you will have to clean it of debre once in a while. I take the defreezer and heater out in the summer.
The main reason for new fish death is shock, that's why when you add new fish to any aquarium or pond you float them in the bag they came in until about ten minutes. The other reason for shock besides sudden temperture changes is sudden PH change beyond .2 and even some more delicate fish get a liitle shocky with that small change. So your next step after floating the bag for ten minutes is to open the top of the bag keeping the new fish inside still and adding small amounts of the pond the water to the bag every five to ten minutes for about 30 to 45 minutes allowing your fish to adjust to gradual changes in the Ph. If you have a new pond and the water is aged and these are the first fish, you can skip the previous step by adjusting the pond ph to match the aquarium store water ph. Your aquarium store can give you the right products to age the new pond water(bacteria starter] Remove chlorine (water conditioner) and Ph testing and adjusting kits. I always buy the largest cheapests quantities of these prducts, and these are the same proucts used for inside freshwater aquariums, as well. You will also want an algae killer and algae scruber w/ a long handle { if your have a plastic pre-form pond}, which can get out of control any time of the year, but especially in the summer months.
I like my new pond pump and filter I just bought this winter at Petsmart, it is a flat style filter about 10 x 14 that sits on the bottom of the pond w/ the pump built in and it doesn't tend to tip over like the pumps w/ the cube stlye filters that attach on the side. It also doesn't seem to clog as often, I can go 3-4 weeks without rinsing the filter material depending on how many times I've cleaned debree.When you have a really small pond you will have to clean it of debre once in a while.I changed the filter maybe about once in the last six months.I hope this info helps you to enjoy your outdoor pond. Spicey