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New Pond

The key stages of creating your brand new garden pond.

Creating a pond can be a very rewarding addition to your garden, but there are a few things to consider beforehand. The first thing to decide is what species of fish you want to keep in your pond, or if you want any fish at all. Traditional garden ponds are usually planted and contain goldfish and similar species. Koi carp need much larger volumes of water as they grow bigger and will destroy most pond plants. The third option is to create a wildlife pond without fish to entice wildlife into your garden. Focus on native pond plant species and a shallow beach area for wildlife to enter and exit. Wildlife ponds can be of any shape or size and often will not need filtration if the balance is right.

What species of fish should I build my pond for?
Fish choice is a crucial decision but is often overlooked by pond designers. The amount of space required, budget and upkeep demands are all higher for koi than goldfish. Aim for at least 1000 gallons (4546 litres) for koi with a depth of at least 1.2m and a strong, capable filtration system to keep the water quality in top conditions. Goldfish ponds can be many shapes and sizes, with no essential minimum. However, a partial depth of at least 0.5m should be maintained to prevent complete freezing of the water in winter. Filtration is also essential in traditional goldfish ponds, but these systems are often smaller and easier to manage than those required in koi ponds. Pond plants benefit the biological processes of the water by absorbing nitrates and phosphates and help shade the pond. This can help reduce problems such as duckweed, and can help keep the water cooler: aim for at least 30% coverage for the best results.

After choosing which fish you wish to keep it is time to think about the positioning of the pond within the garden. A pond should be sited in an open area free from overhanging trees where it receives sunlight for approximately 50% of the day. Decaying leaf litter and penetrative roots from trees and/or shrubs very close to the pond will cause long term issues with the pond’s lining and water quality. You should also consider positioning the pond in an area with easy access for water and electricity supplies for topping up the pond and running the equipment. If the garden is sloped, higher positioning of the pond should be considered to prevent excess water runoff after heavy rainfall, as ground nutrients and contaminants can cause problems both visually and chemically.

The type of pond you are designing should also influence your ornament choice. For wildlife ponds, large rocks can be an attractive, natural effect which simultaneously provide habitats for wildlife and which can mimic natural, slow-moving water bodies. Conversely, for koi or goldfish ponds, such ornaments should be avoided if possible, particularly items such as rocks with jagged edges. Events such as spawning can cause fish to swim rapidly around the pond and can result injuries as they crash into such objects. If you do want to add some ornaments to your pond, consider smooth stones and waterfalls (which will increase aeration) for your features.

When should I start my pond?
This is a popular question that has two meanings and two answers. For those looking to build a new pond, the best time would be spring. You will then have the majority of the gardening season to settle in the fish and plants and prepare them for the winter. A pond can be installed any time of year, but if constructed in the latter months (September onwards) it is important to consider you may not be able to add livestock until the following spring.

Owners of existing ponds will also ask the same question every year, as life tends to hibernate over the winter months and reappear in the spring. Re-starting an existing pond usually involves some spring-cleaning: performing a partial water change, removing leaves and silt from the bottom of the pond and cleaning the filter sponges. Friendly bacteria levels drop during winter so it's important to add a bacterial supplement such as Live Filter Bacteria (Mature), or Filter Bugs. These products help to kick start the beneficial bacteria in your filter which prevents any fluctuations in water quality during the first weeks of spring.

When you are restarting your pond after the winter, it’s also a good idea to check your fish for signs of damage or ill health. Treat your pond with Anti-Parasite & Fungus (Eradick) if you see any evidence of ill-health such as white spot, fungus, Trichodina and Costia. Alternatively, treat your pond with Anti-Ulcer, Fin-Rot & Flukes (Bacterad) if you notice evidence of skin/gill flukes, tail/fin-rot and ulcers.

Water Testing
Testing water quality is an essential part of keeping a pond healthy. Clear water can be hiding some nasty chemical imbalances and, if left unchecked, can cause some serious health problems. Most specialist aquatic stores will test your water upon request, or the Pondlab range of products are fantastic and simple to use at home.

The three most important tests to perform on a regular basis, particularly when starting up a new pond, are ammonia (NH3), nitrite (NO2) and pH (acidity). The Pond Water Mini Test covers all three of these tests and is an essential product for anyone who is starting up a new pond. Ideal parameters are 0 for ammonia and nitrite, and a pH value of 7-8. When starting up a new pond, these parameters will vary during the maturation process of the biological filter. This can take several months, so the addition of a bacterial supplement during the early stages of a pond will help keep the NH3 and NO2 values low.

Test weekly, especially during the first 8 weeks, to make sure toxic levels of NH3 and NO2 are not reached. The pH will go down naturally over time and this is why partial water changes are important to replenish essential minerals which have been lost. Tap water should always be used over rain water and it is important to use a good quality dechlorinator, such as Chlor-Go or Tap Water Chlorine Remover (Aquasure), which will remove any harmful substances before they cause issues in the pond such as skin irritation, destruction of filter bacteria, or fish illnesses.

There is a wide selection of water testing strips available. However, the advantage of using the Pond Test Kits range of liquid test kits is their improved accuracy. They have been formulated to be incredibly easy to use: simply take a sample of water, count the drops and then compare to the colour chart.

Pond Filtration
Pond Filtration is an absolute must! Unless the pond is a heavily planted lake with a natural feed of water in and out, natural biological activity will not be enough to sustain life.
Pond filters perform 3 main tasks:
    1) They remove harmful substances from the water to keep the water in top quality
    2) They remove particles from the water column and pond floor, improving water clarity
    3) They improve oxygen levels as the water re-enters the pond from the filter.
It is vital to leave a filter running 24/7, the exception being wintertime if the cold weather threatens to freeze the water inside the filter. If the filter is turned off, remove water from the UV casing to prevent any breakages, but the general advice today is to leave the filter running 365 days a year.

Pond Filtration has 3 main components: biological, mechanical and chemical.

Biological filtration is the core of any filter as the friendly bacteria that grows inside digests the toxic ammonia and nitrite. These bacteria will grow anywhere there is a constant flow of water. High surface-area filter mediums are used to maximise bacterial activity. Foam is most traditional, but plastic media that is kept moving by the use of water or air is becoming popular in modern filters. Ceramic media and volcanic rock remain popular in koi setups due to their high porosity and surface area.

Mechanical filtration is where dirt from the pond gets trapped in foams or sieves and is then removed from the filter by washing. It is important to use water from the pond to clean these media to prevent killing the good bacteria living in the sponges. Clean regularly to prevent loss of biological activity, as friendly bacteria grow less in dirty foams.

Chemical filtration is used less in ponds than indoor aquaria but is a great way of removing harmful substances rapidly whilst the filter is establishing itself or in an emergency. Zeolite removes ammonia much faster than biological filtration can and is useful in the spring whilst bacteria levels are still low. Zeolite can also usually be recharged in a salt solution, so can be used many times. It is a great tool to have in case an ammonia spike is recorded on a regular testing of water.

Most filters rely on more than one type of filter media. This is to help with the transitioning of friendly bacteria when cleaning or replacing filter media. It is important to never clean the entire filter at once to allow some biological activity to remain. Bacteria numbers will re-establish quickly once the filter media has been replaced in a mature system.

How many fish should I have in my pond?
As different species of fish grow to different final sizes, a stocking density based on the number of fish in a given volume isn’t very meaningful. Instead, the metric of ‘inches of fish per given volume’ is a much more appropriate and accurate equation to work with. The ideal stocking level for a pond is 1 inch of pond fish per 8 gallons (36 litres). A typical 500-gallon (2273-litre) pond would allow a maximum stocking of 62.5 inches, allowing room to grow. Do not be misled into thinking that 60 x 1-inch goldfish can be added to a 500-gallon pond: a goldfish should attain a length of 12 inches, so realistically 5 goldfish is a much happier stocking density!

Koi keepers often stock their ponds at a higher rate than garden ponds - this is why filtration tends to be larger and more capable. High stocking levels without adjusting for it will lead to poor growth, bad water quality and poorly fish. Many koi ponds will have a stocking level of about 1 inch of koi per 6 gallons (27 litres). Therefore, a 1000-gallon (4546-litre) koi pond would allow 165 inches or about 6 koi, considering their fully-grown size of a little over 24 inches. However, the more space you provide each of your koi, the better their growth rate and the easier it will be to maintain water quality.

Introducing fish to the pond is probably the most exciting part of the whole process, and with it should come some patience. Once filled with water, the pond should be left at least a couple of weeks to settle in before adding any livestock. Plants can be introduced in the meantime, as these are less affected by fluctuating water quality.

When adding the first fish, it is a great idea to add a bacterial supplement to the filter at the same time. This helps reduce any sudden spikes in ammonia and nitrite, Filter Bugs or Live Filter Bacteria (Mature) are the products you’ll need. Benefits can also be seen if these supplements are added monthly during the warmer months to help biological activity in the filter.

Introducing fish to the pond

Before you add your fish to your pond, whilst the fish are still in the transportation bag, it is a good idea to add the appropriate dosage of Tap Water Chlorine Remover (Aquasure) to the water in the bag. This product contains special colloids which help to reduce stress, which will help to ease your fish into their new home!

It is essential to ensure the temperature of the pond water and the water in the bag is the same. This can be achieved by floating the sealed bag on the water’s surface for 20 minutes. During transit, the water inside the fish bag will warm up. Adding the new fish straight to the pond will cause sudden shock and can cause severe problems, so ensuring you go through this cooling period beforehand can prevent these occurring.

You then need to mix the water from the bag with pond water. To do this, open the bag and roll down the sides to create a floating ring and slowly add water into the bag. This allows slow adjustment to any differing water parameters, especially pH, to prevent shock. After a further 20-30 minutes, the fish can be released into the pond and the bag removed.

This gradual process is important for the fish to settle in stress-free. The fish will generally swim to the bottom and hide for a few days until they have settled into their new home. You can offer food to them after a couple of days but if they are still hiding make sure to remove it before it pollutes the water. Remove uneaten food after 20 minutes of no activity. Fish can go for an extended period of time without food so if they are not coming up to feed, don’t worry, they will eventually!

For all ongoing maintenance of your new pond, be sure to maintain your pond using the NT Labs Pond range, feed your fish with Medikoi foods, and regularly monitor your water quality using Pond Test Kits Test Kits!

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Tagged in: Outdoor