A fish pond can be the crowning achievement to a perfectly manicured and landscaped yard, or it can be a simple tub with a few minnows. But no matter what kind of pond you are looking to build, you’re going to need to carefully plan it out and build it right – unless you want to deal with algae infested waters, choked with dead fish.
Thankfully, ponds aren’t overly difficult to build, and if you spend some time making sure that you do things right the first time around, you’ll have years of trouble free enjoyment ahead of you. Before you start building your pond, you’re going to need to know a few things though – the type of fish you are planning to keep, where you want to construct the pond and how large the pond is going to be.
Type of Pond
Before you do anything else, you need to determine what kind of fish you want to keep in your pond. The type of fish will have a significant impact on the size and cost of a pond, so always start with the fish you want and work backwards from there. With that being said, the two most common types of fish that people keep in a pond are goldfish, and koi, so we’ll focus on those fish for now.
Many people want to dive right into a huge koi pond, without having any fish keeping experience. But a better first choice would often be goldfish. Not only can goldfish be had for a fraction of the price of koi locations, but they are an incredibly hardy and forgiving fish. Plus, they can also be housed in smaller ponds, so you don’t have to invest in a backyard lake right off the bat.
The minimum size for a goldfish pond is usually listed as 100 gallons (378 litres), but a more realistic minimum size is somewhere around 250 gallons (946 litres). A good rule of thumb is to have 100 gallons for the first goldfish, and to provide 30 gallons for each additional goldfish that you add.
When planning the depth of the pond, your location, or more accurately your winter comes into play. Goldfish ponds need a minimum depth of 2 feet (0.60 metre), but that number increases to 3 feet (0.91 metre) if you live in a region where the water will ice over in the winter.
Let’s face it – when many people think pond, they automatically think koi ponds. And who can blame them? A well designed koi pond is stunning, and creates an oasis and calm and tranquility in a person’s backyard. Of course something that
The problem with a koi pond, is that even the smallest ponds still need to be enormous. The water needed to keep several koi healthy is vast, and the minimum size for a koi pond is around 1000 gallons (3785 litres). And a more realistic size is pegged at around 2500 gallons (9463 litres), though you can make do with less.
Not only does the pond have to be large, it also has to be deep. While there are reports of people successfully keeping koi in as little as 1 foot (0.30 metre) of water, the true minimum depth required for koi is 3 feet (0.91 metre). And if you wanted to double number that to 6 feet (1.82m), you would likely see better growth and healthier fish.
Most koi can grow to river monster sizes, and because of this they will need large amounts of high quality food, and powerful filtration – both of which add to the costs of keeping the fish. Depending on the type of koi that you purchase, they can also be very expensive, so if you are new to fish keeping, you may want to start with an easier fish.
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Minnows and Other Fish Ponds
For many years it was rare to find anything but koi or goldfish in a pond, but in recent years, numerous other fish have started to become more common. Several species of sunfish, rosy red minnows and mosquitofish have started to become more popular and the smaller species have the added benefit of being able to survive in much smaller ponds.
When it comes to the smaller fish, they can survive in ponds as small as 30 gallons, though a pond this small is often a nightmare to maintain. As a rule, the larger pond that you start out with, the easier that it is to maintain.
Sunfish are a bit more difficult, and thanks to their rapid reproduction can quickly overrun a pond – which results in stunted fish. If you are considering a pond for sunfish, you should follow the size guidelines for koi ponds, and even 2500 gallons may be too small for sunfish. Most people only experience success with sunfish when they add a few large predator fish to keep their numbers down and the population healthy.
Once you have decided on the size of your new pond, you will need to identify a location for it. The location of a pond can have an enormous impact on the water quality and health of the fish, and numerous new fish keepers have experienced failure when they placed their first pond in a least than ideal location.
So where should you place a pond then? You should only start digging the pond after you have taken into consideration nearby trees, the grading of the lot, the sunlight that the area receives and most importantly, any nearby hazards.
One of the first things that you need to look at, is the location of nearby trees. Falling leaves can be a disaster in a pond, and will quickly foul the water if you don’t keep on top of removing them. That’s not to say that ponds have to be located far away from any trees – they just need to located strategically where few branches will directly overhang the pond.
The amount of sunlight that the ponds receives is also something that you need to take into consideration, and ideally you want the pond to received between 4-6 hours of direct sunlight every day. However, if the pond receives more than 8 hours of direct sunlight, you will likely experience temperature fluctuations and algae overgrowth in the ponds. If it does receive more than 8 hours of sunlight, make sure that at least part of the pond is shaded to provide shelter for the fish.
The grading of your lot is something that many people don’t even consider when building a pond, but you want to grade the lot in a way that still complies with your local regulations, and also drains a minimum amount of rain water into the pond. While most rain water is perfectly harmless, any water draining into the pond may carry fertilizers or other toxins with it. While it may not always be possible to grade the area around the pond to ensure that no runoff drains directly into it, you should at least try to minimize it as much as possible.
The most important thing that will influence the location of a pond is any nearby hazards. Make sure that the pond isn’t located close to any overhead power lines or any buried utilities before you start digging it. Many areas offer free locate services for utilities, and you should always take advantage of that before building a pond.
After you have chosen what type of fish you are planning to keep, and where you want to build the pond, it’s time to get down to the details of how you want to construct it.
When you begin to layout your pond, make to remember the minimum size requirements for the type of fish that you plan to keep. Most ponds should be at least 2 feet (0.61 metres) deep, and 3 feet (0.91 metres) is really the minimum if you plan to have fish overwinter in your pond.
A good rule of thumb for the size of a pond, is that it should be at least twice as wide as it is deep. This isn’t a hard and fast rule, but it does help with the oxygen exchange in the water. If there isn’t sufficient surface area, you could find yourself quickly running into problems when you add fish to the pond.
Digging – When it comes to digging the pond, you should always leave a shelf around the edge of the pond for plants, and a good depth to use for the shelf is around 1 foot (0.3 metre). The rest of the pond should be angled downwards in a gentle slope. Make sure to remove any rocks or debris that may damage or puncture the pond liner after you finish digging.
Filters – After you have finished digging the pond, it’s time to excavate the location of the pond skimmer, or construct the water fall if you are using a pond filter. Make sure that you bury them to the proper level, since this can be a extremely difficult to redo after the pond is up and running.
Line the Pond – After the pond has been excavated, you can install the pond liner. Rubber pond liners are generally easier to use, but larger ponds will need pond liners – unless you have the budget to construct them out of concrete.
Edging the Pond – After the pond has been lined, you can then adds stones or coping around the pond. You can also backfill with soil around the edging, and if you are using small stones or expect a lot of traffic around the pond, then you can mortar the stones into place. It also helps to fill in the area around the stones with soil.
Add Plants and Fish
After you have finished constructing the pond, then it’s as simple as adding the fish and plants. It’s always best to add plants as soon as possible, which will help to combat the inevitable algae in the pond. Fish can be added after the pond has finished cycling, and the water has been treated to remove algae.