Goldfish in ponds


Fish Crazy
May 13, 2020
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Hi. Just would love some experienced advisors to comment on how goldfish and koi survive UK ponds outdoors?

If anyone of you have them, I'd love your experience on the following for UK OUTDOOR/Winter survival.

1) Which pond plants have had most success?
2) Mechanical filtration system/brand?
3) bio filtration types, where to buy good rocks, sand vs gravel, best lining for bacteria to grow on as well!
4) which snails, any other live bottom feeders good for surviving uk winters?
5) do you do water changes still?

Any other info you have personally discovered to be vital for the fish's health please.

I will research all of your suggestions.

My recent goldfish rescue has inspired me to try a pop up or above ground pond structure since I can't dig.

Thanks :)
As long as the pond doesn't freeze solid, they can sit at the bottom of the pond in a dormant state while the weather is cold. When it warms up they wake up and breed.

Vallis, Ludwigia, Elodia and Hornwort are all good plants, as is Duckweed but it dies off when it's frozen.

You can float a tennis ball or plastic ball in the pond to stop the water freezing completely across the top.

If you have lots of plants, you don't always need a filter. Filters can be external trickle filters that consist of a box or rubbish bin filled with filter media/ materials. The pond water is pumped into the top of the bin and flows through the media and out a drain b\hole in the bottom that goes to the pond. Internal filters are usually sponges fitted to the intake of the water pump. You can have both types at the same time. The sponges protect the inside of the pump and help trap gunk.

You still do water changes if you can, but they don't get done every week. Most people do a 50% water change once a month or once every couple of weeks during warmer weather, and no water changes during the cooler months.

There are numerous materials to line a pond with. Thick plastic, rubber or concrete are all used for ponds. If you plan on keeping the for for 20 years then build it with brick & concrete. The rubber can be expensive but lasts 10-20 years. Plastics come in a range of thicknesses and can last 2-20 years depending on the thickness.

Ponds should be at least 3 feet deep so there is less chance of the water freezing sold to the bottom.

For above ground ponds you can look for aquaculture suppliers. They usually have nice size plastic ponds that can sit above ground. There is a company in my town that has an 8 foot diameter pond that is 4 foot high. I would love it but don't have anywhere to put it.

One of the places I worked at had 10 foot diameter galvanised rainwater tanks that had been cut in half so they were 10ft diameter x 3 foot high. They were put on top of the soil and lined with a heavy duty plastic pond liner. The same place also had 200 litre wheelie bins (rubbish bins on wheels) all around the edges of the property and each bin had a water lily and fish in.

We are in Australia so the water doesn't freeze here but the more water you have, the less chance of it freezing solid. You can also put some bubblewrap plastic on the surface to help warm the water if any sun shines during winter. Just leave a small area open for air to come into contact with the water.
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