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Pond Care Calendar – a year in the life of your pond

Water Gardening Calendar

A  month-by–month  guide to  maintaining your pond



Usually the coldest months of the year and the quietest time in your pond. Most fish will be dormant at the bottom of the pond and will not be interested in feeding if the water temperature is below 6oC. Throughout the winter the fish live off the fat reserve they have stored during warmer months. There is a popular myth that leaving a ball floating on the surface will leave an ‘ice hole’ but in really cold weather the ice just freezes around the ball!

The best way of preventing ice forming over the surface is to add a pond heater and/or keep your   waterfall running. This will keep a small area free from ice, which allows harmful gases to escape from the pond and oxygen to diffuse in. Under no circumstances should you forcefully break through ice as the shock waves can be very stressful to fish and wildlife.



With the arrival (hopefully!) of milder weather your water garden will start to come back to life. If your pump and filter have been switched off over winter, now is the time to restart the biological systems. Check the pump impellor can rotate freely (e.g. no snails or leaves blocking it up!) then switch the pump on. Over the winter the beneficial bacteria in your filter will have died off, so it is always recommended that you add a bacteria starter culture to kick-start the bacteria colony.

After a couple of weeks your filter should have matured, and it is time to switch on your Ultra-Violet Clarifier, after changing the bulb and ensuring the quartz sleeve is clean.

Fish will appear more active by now, and can be fed sparingly on a quality food that is designed for use at lower temperatures e.g. a “spring” or wheatgerm-based pellet. Observe your fish closely after their ‘winter hibernation’ as they are at their weakest after fasting through the coldest months.

As the water temperature rises, dormant parasites in the water also begin to multiply, and will often take advantage of the weakened condition of the pond fish. To avoid an infestation, be vigilant for  any signs of infection and have an anti-parasitic medicine ready just in case.



Water temperatures should have stabilised now to a point where the fish are feeding regularly.  Continue to use the low-temperature food as your fish will still be ‘sluggish’ and unable to digest large quantities of higher protein food at this time. Over-feeding in the spring will also place        additional strain on your filtration system, which can in turn lead to poor water quality and a       deterioration in the health of your fish. Testing the water quality in your pond is an important part of fish keeping.  Regular testing of water conditions (ideally weekly or fortnightly) allows you to    monitor any build-up of harmful pollutants, particularly Ammonia (NH3 and NH4) and Nitrite (NO2)  which can be fatal to your fish. Monitor the pH levels as the water can become acidic over time,  especially after heavy rainfall and flooding.  Simple water test kits are available and will save you time and money in the long-run. Prevention is better than cure!



May is the best time for pond planting—the more plants you have, the less algae you are likely to suffer with! If you are re-potting last year’s plants, use a good quality aquatic compost and line the planting baskets with hessian. This stops the compost escaping into the pond (which would cloud the water and promote algae growth) and restricts any rampant root growth.

This is also an ideal time to introduce new fish to your pond. All of our fish have been quarantined before they are sold, but keep a watchful eye on your new fish for any signs of distress or        abnormal behaviour. Bacterial, fungal and parasitic problems can be triggered by the stress of  moving or by a deterioration in water quality.

You should now be able to switch to a ‘summer food’ – remember it is best to feed sparingly with a high quality feed than over-feed with a cheaper brand which often contains additives that can cause murky water. Most fish would happily eat all day(!) but they actually only need 2-3 pellets or sticks per meal.  You might find it easier to use a floating feeding ring to keep the food in one place, and train the fish to return to the same place to feed.



Your pond should now be brimming with life and your fish eager to feed. you can now feed the fish more often, but be diligent with your water-testing—levels of Ammonia, Nitrite and Nitrate can rise quickly with the increased feeding regime, and if the levels become too high you may need to take action to prevent illness in your fish or excess algae growth.

Plant growth rates have increased by now, so June is an ideal time to add aquatic plant fertilisers to keep your plants in good condition.


July– August

It is now the height of summer (hopefully!) and most people spend many hours around their pond at this time of year. Fish should now be on a high-protein food so they can begin to store energy to help them through the winter months. Again, be aware that increased feeding can lead to a  deterioration in water quality, so continue to monitor your water conditions with your test kits.

If your pond does not have a fountain or waterfall, it may be necessary to introduce a pond air pump for additional oxygenation. The warmer the water gets, the less oxygen stays dissolved in it, and oxygen starvation is one of the most common causes of fish death throughout the summer months.

Hot weather can also cause water loss from your pond through evaporation. When you use tap water to top up the water levels, remember to use a dechlorinator to remove chlorine, chloromine and various other harmful substances found in tap water. Forgetting to do this can cause irritation to the gills and can lead to fungal and bacterial diseases. Leaving tap water to stand for a few days does not remove all of the harmful substances.  Topping up with rainwater can be a good alternative but rainwater is often acidic, so test the water in your water butt before you add it to the pond and use a pH buffer to alter the pH if necessary.

If you’re going on holiday, try to persuade a neighbour or friend to feed your fish for you and have a quick look to check they all seem healthy. Alternatively, you can buy a holiday feeding block which will slowly release food into the pond while you’re away.


September– December

In the autumn it is time to switch back to the low-temperature wheatgerm food. If the water   temperature falls below 6°C, do not feed the fish at all as they won’t be able to digest the food and it could cause internal infections. Clear all dead leaves from your pond plants and use a cover net to prevent leaves and debris from falling into the pond, which can decompose over the winter and cause poor water quality. Floating plants can be moved indoors or into a greenhouse over the winter months as they are not frost-hardy.

Once the fish have stopped feeding, the pond can be prepared for winter. If you choose to remove the pump, U.V. Clarifier and filter, clean each component thoroughly and store inside until spring. In most ponds it is best to leave the pump and filter running throughout the winter. Pumps are usually raised to mid–water level to ensure minimal disturbance at the bottom of the pond where the fish are hibernating.

Autumn is a good time to use a pond sludge vacuum to remove debris from the bottom of the pond, which would otherwise rot over winter. The vacuum lets you target and remove the ‘sludge’ at the bottom of the pond without stirring it up and clouding the water. The waste water and sludge from the vacuum is very rich in nitrates and can be used as a free eco-friendly organic     fertiliser for your flower beds!  You can hire our vacuum  – ask us for details or a demo!



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