KEEPER BASICS: SPRING POND MAINTENANCE

By Dr Dave Pool

Once set up, there is relatively little maintenance required to maintain a pond’s condition and the health of the fish and plants within it. The maintenance tasks that are needed are largely dependent on the season of the year and in particular the water temperature. This will vary depending on where you live. However, the activities of the fish and plants give a useful guide to when feeding should begin, filters are turned down, heaters turned on and much more.

Feeding

During the spring, the days will begin to lengthen and the water temperature in your pond will start to rise. At water temperatures above 8C, fish will become noticeably more active and will begin searching for food. Initially, just feed them once a day on a few floating food sticks or flakes. Don’t be tempted to feed too much too quickly. The first warm days are usually followed by cold conditions.

In late spring, they will be feeding ravenously to build up their strength after the rigours of winter and to develop reproductive tissues. At this time, they can be fed 1 – 2 times a day, but only on as much food as they will consume in about 5 minutes.

Water circulation and filtration

The pump and filter should be restarted 1 – 2 weeks before you start regularly feeding your fish. Gradually increase the amount of food that you give to ensure that the filter bacteria can increase sufficiently to cope with the resultant increases in waste.

As temperatures increase, the pump can be positioned in the deepest part of the pond. Pumps that have been running throughout the winter can be turned up and lowered to the pond bottom.

Waterfalls and fountains can be switched on in mid to late spring when water temperatures are consistently above 8C.

Disease

When the fish awaken from their ‘semi-hibernation’ they will be very weak and susceptible to infection by parasites. Watch out for signs of fungus, gasping, scratching against underwater objects or a grey slimy coating to the skin. You may also notice one or more fish being very lethargic, keeping away from the other fish or remaining still on the bottom or near the water surface (sometimes close to the filter or waterfall inflow).

Treating the pond with a general external parasite remedy is advisable, although the worst affected individuals should be removed to a separate treatment container. Some pond keepers add a preventative treatment to their ponds in April to kill any parasites before they adversely affect their fish.

Algae problems

Algae growth, either in the form of blanket weed or green water, can be a problem in the spring before the plants become established. Algae can respond very quickly to warmer and brighter conditions in spring and will start to multiply rapidly. Later in the spring, the water plants will grow more rapidly and outcompete the algae for nutrients and start to shade the water, resulting in the algae growth reducing and the water clearing.

Control can be achieved by using an appropriate algae treatment to reduce the number of algae in the pond. Then, encourage fast-growing plant growth by removing nutrient-rich sediment to prevent it from coming back. UV units are also a great way to keep the pond water clear and should be switched on in early spring.

New plants

The spring is an ideal time to introduce new plants into your pond. The safest and most convenient way to plant your pond is by using the plastic baskets available from most stores. These come in a range of convenient sizes and permit the easy re-arrangement of the plants at a later date. The baskets are best filled with good quality nutrient poor soil or a special pond planting media. Large gravel should be added to the top of the basket to prevent the fish disturbing the soil and clouding the water.

Introducing fish

The spring is a good time to add new fish to your pond. Always select healthy, active individuals that show no sign of disease. Avoid those with fins that are folded against their bodies, with obvious parasites and individuals that are sulking on the bottom of the container or gasping at the water's surface. You shouldn’t purchase any fish from containers in which other unhealthy or dead fish are present as they may also be diseased.

Don’t buy too many fish at one time. It is better to gradually increase your fish population over several weeks to allow the filter to build up its bacteria load and be able to break down the extra fish waste that will be produced.

When you get the fish home, float the bag containing the fish in the pond for 10 – 15 minutes to ensure the water temperature in the bag and pond are the same. Then, gently release the fish into the pond

Spring clean your pond

Although the water will still be on the cold side, it is often best to do any cleaning in early spring, before the frogspawn has hatched, as this prevents you from accidentally removing lots of tadpoles from the pond.

Carefully look through any debris that you remove for signs of life. Dragonfly and damselfly nymphs, newts, snails and any other pond life can be accidentally discarded when cleaning. If you are adding tap water to the pond, use a conditioner to remove any chlorine, which could otherwise harm pond life.

Tree blossom

If you have fruit trees in the vicinity of the pond, the blossom may be a problem in spring. Remove any blossom that falls into the pond before it sinks. If there are many fruit trees you may need to put a net over your pond for two weeks while the problem is at its worst.