Once your pond is built and watertight, you can start adding the goldfish pond equipment, fixtures and eventually, live plants!
It may prove helpful to only half-fill your pond with water until after you have situated your decorations and fittings, in order to provide easier access to the bottom of the pond and allow you to see everything that you need.
Bear in mind that some goldfish pond equipment, such as filters and pumps, may not be able to “run dry,” i.e. function without any water passing through them, so you will not be able to test everything out fully until the pond has been filled.
Adding plants and fixtures to a goldfish pond
Live plants are extremely beneficial when added to ponds – it is always recommended to add plants to a natural pond as they come with many bonuses that will make your life keeping a pond much easier.
There are a few things you should know however, before adding plants, as there is a wide range of options and ways to install them to your pond, each with varying levels of success.
Adding decorations and fixtures to a pond
Start with your large, solid ornamentation, such as rocks and decorations.
This is what is known as the “hardscape”; it is all the non living things in the environment you add for decoration.
Place the hardscape into the pond before you add the substrate, in order to provide a firm surface for them to stand on.
Goldfish are also quite fond of digging sand and substrate, and if rocks are dug underneath they can collapse, potentially cutting the liner or even crushing your goldfish! So it is very important to always place the rocks and decor first, or at least bury them under the substrate a little.
Make sure that everything is situated securely, and will not collapse or topple over and injure your eventual fish.
Also be sure that there are no places your goldfish can get stuck. This may sound silly, but it is actually very common for goldfish to get themselves stuck between decor and liner, or between a tight space.
It is best to avoid this if possible, check all around the pond for any places where you think they could easily fit into.
Remember, larger goldfish aren’t good at swimming backwards, so if they can’t turn, sometimes they get stuck. Avoid narrow spaces, like placing plant pots against walls.
Adding substrate to a fish pond
Next, add your substrate, such as gravel or sand, ensuring that it has been thoroughly rinsed out with clean water to remove any debris first.
Also be sure that the substrate is indeed fish safe! Many garden centres will have a symbol of a fish stating that it is pond safe over the bags of substrate, meaning it is safe to use.
The water will need a while to settle after this, and may appear dirty until it does so, but this is just dust from the substrate; it will eventually clear up and is nothing to worry about.
What equipment do you need for a goldfish pond?
Now you are ready to add the essential equipment that your pond needs to be healthy, such as the filtration system and air pumps.
At this stage, you will also need to work out how and where you are going to locate the power lines to run these, and ensure that they are secured and safe to use.
Make sure that the aeration pump or pumps are situated in such a way as to efficiently move the water around the pond, and provide enough oxygenation to the lower reaches of the pond.
The best place to put an air stone is usually in the centre, this makes the radius of the surface agitation more spread out and balanced.
Place your air stones at the bottom of the pond, so they can generate uplift and keep gaseous exchange flowing through the whole pond.
Ensure that the filter is located in a good spot to filter the water and also remain within easy reach for cleaning. If the filter is gravity fed, make sure it is a level above the pond, so the clean water can flow back into the water body.
When the pond has been filled, try out all of the equipment to make sure that it works properly. When you are happy, leave the equipment running and keep an eye on it, check for any leakages or dysfunction along the way, making changes where necessary.
Adding plants to a pond
After you have decorated the pond and got all of the equipment up and running, leave the pond to settle down for a few days before adding your plants.
This is to allow:
- the temperature to settle;
- excess chlorine to evaporate after dechlorination;
- for the pond to be properly oxygenated and tested for stability.
Plants are an excellent addition to any pond and are not simply a decoration, but are a living thing and should be treated with as much respect.
Pond plants can grow very quickly, become enormous sizes, encroach on your pond with their roots and stems, kill other plants off, drown, dry out or even be poisonous! This is why it is very important to select the right plants, and again, to treat them as living things, not a decoration.
Plants are really good in the fact that they consume harmful toxins that your fish produce (ammonia, nitrite and nitrate); the most valuable of these being nitrates, as these can not normally be removed without a water change.
Plants feed on nitrates, removing them from your water and making it more habitable for fish and other animals.
Plants also produce oxygen and provide hiding space for small fish and invertebrates like snails, which are an important clean up crew for your pond.
There are two main types of pond plants, these are “MARGINALS” and “OXYGENATORS” and each fill different roles.
These are plants which grow along the sides of the pond, in the shallower parts and grow up out of the water, with their roots submerged. These are great as barriers on the sides of the pond and to provide cover from above.
They also grow very fast, meaning that they consume a lot more nitrates than oxygenators.
There are many different species of marginals to choose from, but be sure to only use plants that are from your native area, as they can be extremely damaging to an ecosystem if invasive.
Even if a small piece of the plant is cut off, it can grow into a new plant and take over. This is why it is important to properly dispose of them if you ever have foreign species that you cut back, and not to just throw them down on grass as they can regrow.
Different marginals have different conditions at which they grow, and some like to be placed in deeper water or more shallow water. Most garden centres will have a guide on the pot the plant comes in, which will show how deep or shallow you should place the plant.
Marginals are often deciduous plants, and will die off and go brown over winter, but should always come back in the spring. Some stay year round and others are annual and only live for 1 or 2 years.
Here are some excellent suggestions for pond marginals which are easy to grow and are very versatile:
- Barred horsetail
- Orange peel
- Iris (can grow large)
- Fibre optic plant
- Scarlet lobelia
- Bull reed (grows large)
- Variegated reed (grows large)
- Sweet grass
These are plants which grow fully submerged, and again, these have different depths which they do well at, but most will grow best at around 3ft deep; others float to the surface.
Oxygenators are good as they provide extra cover for hiding and spawning, consume nitrates and release oxygen into the water.
Similar to marginals, not all of these plants stay year round, but some do, such as water soldiers, which sink to the bottom during winter and float during summer.
Aquarium plants can also be used in ponds with varying levels of success, while many can survive, remember that many tropical plants come from climates which do not have a winter like some temperate areas and will die in the colder months.
However, many can still be used over summer or in a greenhouse pond.
Here are some really good oxygenating plants to try that will last year round:
- Water soldier (grows large)
- Elodea densa
- Coontail / Hornwort
- Egeria najas
- Lily pad
- Water lettuce
- Water hyacinth
- Duckweed (grows extremely fast)/(will be eaten by goldfish and carp)
Here are some good plants to try over summer. Just know that while they may survive winter, they should ideally be taken indoors so they do not die:
- Anubias (bateri and nana petite)
- Java fern (will definitely die in cold months)
- Ratalia walichi
- Java moss
- Jungle val
- Pogostemus stellatus
Introduce plants gradually, and plant them with consideration for their needs in terms of lighting and water flow.
Plants also require food and minerals, much like animals. As mentioned, plants will largely feed on nitrates produced by your fish, and light.
However, you should still ideally feed them with minerals when you buffer your pond water hardness and or a pond plant fertiliser, just make sure that it is for ponds and is safe for fish and invertebrates.
How long to leave a pond before adding plants
If you are confident in your build, you can add plants the next day after filling the pond up once the temperature and oxygen levels are stable.
Some people do however, wait a few days to allow some bacteria to grow.
This isn’t really necessary though, as plants do not release ammonia the same way fish do or suffer from it and your plants will still grow the same, accepting that the water pH and temperature are stable.
Plants also speed up the cycle of a pond as they introduce beneficial bacteria and tiny creatures.
How can I decorate my pond edges?
Use marginal plants, rocks, pebbles or ornaments to cover the edges; just be sure that it doesn’t obstruct the pond or equipment as you still want easy access to your pond, while still providing protection.
Naturally, marginals will grow around a pond and cover it, so they may want cutting back if you don’t want this.
Also be sure that any ornaments or stones are secure and will not fall into the pond with a strong gust of wind or be knocked by an animal or child. You can of course secure items in place with cement or even glue, just be sure it is non-toxic.
You may also want to leave space around the edges to place a cover or liner to stop birds or predators from getting at your fish.