Seasonal Pond Care

Once you have an established fish pond, you may be wondering how you care for it throughout the different seasons, weathers and temperatures.

Our guide will run through how you can care for your fish and fish pond in key seasons: winter and summer.

Pond care in Summer

With summer comes high temperatures, more sun and less rain. These factors alter the ecology of a pond and cause it to react in different ways.

Some of these weather effects may require additional action to be taken to maintain your pond.

Warm pond water

The largest and probably most important thing to know about hot weather is how it affects water. Warm water cannot absorb oxygen as easily as cold water – this not only makes it hard for fish and other aquatic life to breathe, but it also affects the pH.

Carbon dioxide also makes water acidic when it dissolves, changing the water chemistry and making it less habitable for goldfish.This is another reason why it is important to continue to buffer your water throughout the summer.

The increased heat and sunlight gives plants a major boost in growth; this growth can sometimes be too much, algaes and blanket weed often overtake in the summer and can choke other plants and filter parts.

Blanketweed should be removed regularly during the summer as it is incredibly fast growing and will clog up your pond.

Fish are cold blooded animals, and this means that their body temperature and metabolism is based on that of their surroundings. With higher temperatures comes a faster metabolism, and so your goldfish will be more active, eat more, grow faster and may even spawn.

Summer pond adjustments

You may want to make adjustments to your pond during the summer, such as adding more plants for shade and cover, which will allow the goldfish to get away from each other, spawn and feel more comfortable.

You may want to feed them more to compensate for their increased appetite.

The increased activity level also means they consume more oxygen. 
This combined with the lower oxygen level within warmer waters means you may want to add an airstone to increase aeration levels and provide better welfare for your fish, during the summer months.

Pond care in Winter

Winter care for ponds is fairly straightforward; you can either break down your pond and take your fish inside, or leave your pond running and leave your fish outside.

The former method is best used on fancy goldfish or for very small ponds, which cannot bear the harsh freezing temperatures of winter.

The latter is best used on natural ponds, or those with koi or common goldfish, as they can withstand these temperature drops.

Keeping goldfish outside in winter

Goldfish are a coldwater fish – this means that their bodies are adapted to withstand very low temperatures, even freezing temperatures. 

A healthy goldfish should be able to survive winter, accepting that the pond provides the right conditions for them.

You can choose to leave your filter on or off during winter. In the UK, generally speaking, temperatures never really reach temperatures low enough to freeze running water, this means you can leave your filters running.

Leaving your filters running keeps the water clean and prevents it from freezing, it also keeps the water oxygenated which is very important.

If you live somewhere colder in areas of America or in Canada, where the temperatures reach very low temperatures below -20C, it may be a good idea to turn off and drain your filters, as the water in the pipes can freeze and burst the plumbing.

If you decide to let your pond freeze over, make sure to break some of the surface, to allow oxygen to get to the water body.

Heating a cold pond

If you find yourself in a difficult scenario, where you need to keep the temperature up for some reason, you can heat a pond, although this can be fairly expensive to do. It is recommended that you use a large heater like a high wattage glass or titanium heater, and you may need to add multiple heaters to keep the temp up.

You should also add a cover to the pond, either tarp, plastic or some other insulating material to hold the heat in, otherwise most of the heat will be lost and electricity will be wasted.

Coralite is an excellent material to use for pond covers; it is highly versatile, cheap and easy to shape, light weight, allows sunlight to pass through it and is a great insulator.

Fish living in freezing weather

If your fish have been surviving in freezing cold weather, they may appear to be staying around the bottom, and will look very lethargic. This is because during cold temperatures (below 10C), fish enter a state called “torpor”.

Torpor is a bodily state cold blooded animals enter when they become a certain temperature – it is a defence mechanism to slow down their body processes and consume less energy when times are tough.

Torpor is a completely natural state and should not be interrupted.

Never try to bring fish out of torpor, as it can shock them and kill them!

Remember, while it may seem cruel to leave your fish out in the freezing cold, they are not like us, and having their body temperature drop is a natural process they are equipped to cope with.

Pond temperatures below 10℃/50℉

When temperatures drop below 10C/50F, you need to move your fish onto a different diet (wheatgerm). This is because the bacteria in the goldfish’s gut that digests protein stops working below this temperature.

Wheatgerm is widely available at nearly all pet stores and fish stores, however, if you cannot find it, try not to feed them on their normal high protein diet, as the food will sit in their stomachs all winter and can cause bloat, infection and all sorts of other issues.

Pond temperatures below 5℃/41℉

Once temperatures drop below 5C/41F, DON’T feed your goldfish AT ALL.

During the coldest winter months it may seem strange, but your goldfish are not using much energy and don’t need feeding. Again, if you do feed them during this time, the food will sit in their intestine all winter and cause a whole host of health problems.

Only when temperatures get back above 5C, you can feed them again. Wait to see if they rise for food, if not and they stay at the bottom, leave them alone.

It is important not to stress your fish at this time, so minimal contact, aside from health checking is best for them.

4 thoughts on “Seasonal Pond Care”

  1. Hello, i’m looking for a water filtering system for my out-door water pond for god fish. I’ts a resued bathtub that I turned into a pond, with water lily plants, and gold fish, what syste can you recommend?

    much thanks Ed.


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