Brightly coloured, confident around humans, and adaptable to a range of climates; koi carp are very popular pets. But, many koi carp live around 30 years, so there are a few crucial points you need to consider to ensure the health and comfort of your fish.
Here, we’ve looked into good koi carp keeping to bring you the one-stop guide for looking after your fish with minimal cost and effort.
Ensure optimum water conditions
Koi carp are hardy creatures and easy to look after, but they can fall victim to health problems if they’re kept in poor water conditions. Typical problems koi carp owners face when it comes to water quality include:
- pH fluctuations due to acid rain or a low KH
- High ammonia and nitrite caused by excess fish waste
- Poor water quality due to inadequate pond equipment
- Not deep enough for the fish to overwinter
These are certainly possible problems you may encounter, but they’re also mainly avoidable and at least simple to correct. A massive 80%+ of koi carp problems are associated with poor water quality, so it’s vital that you provide a good water environment for your koi carp to prevent diseases and other issues.
What is a good water environment? Decent water parameters for healthy, happy koi carp should feature:
- Zero/negligible levels of ammonia and nitrite
- A reading of 20 to 60ppm for Nitrate
- A pH level of between 7-8.5
- Minimum oxygen rate of 6mg/litre
- No chlorine, iron, lead, zinc, or copper
Just because the pond looks clean, doesn’t mean it’s ideal for your koi carp. Along with the above, your koi carp live best in slightly hard water (water with a high mineral content). This water type works to prevent toxins dissolving and so prevents them from harming your koi carp. Harder water also helps prevent pH swings which can be extremely dangerous to your fish.
But, how do you ensure you have a decent water environment for your koi carp? Firstly, get a dechlorinator to treat the water before you add your koi carp to make sure it’s the best it can be from the start. Having a high-quality water pump is essential to maintaining excellent water circulation for your koi carp and installing a good pond filter makes it simple to rid your pond of waste and toxins. It’s vital to check that your pond filter is large enough to clean the entire pond. Since koi carp can grow relatively large, your pond might eventually offer much less free space for good circulation than you predicted. Plus, your koi carp will consume more and more food which means larger levels of ammonia for your filter to deal with.
Check water regularly
Regular checks of your pond water’s quality significantly reduces the risk of ill-health in your koi carp.
So, what is a regular water check and how do we do it? A rule of thumb is to change at least 10% of your pond water every month to prevent toxins building up and keep your koi carp healthy. Buy a water test kit and make sure you check on your water quality once a week, so you can act on any problems straight away.
Remember, fish can look fine for some time in poor quality water, so a weekly water check means you can catch potential problems before they progress into more serious and expensive issues.
Keep the water temperature correct
Koi carp are hardy in the UK climate and survive just fine over winter, even in a frozen pond. If your pond surface freezes over, your koi carp will simply enter a form of hibernation until it thaws — However it can be beneficial to add a floating heater/de-icer, which creates a hole in the surface of the ice to allow for adequate gas exchange.
The body temperature of koi carp adapts with their surrounding water. To thrive, they need gradual change, which means not drastically altering their water temperature.
Air temperature can naturally rise and fall with the day and season, but water temperature doesn’t move quite so easily. As a result, you won’t have to worry too much about the safety of your koi carp.
Choose the right filter
There are many good pond filters out there to help you keep healthy koi carp. The trick is getting the right one for your pond.
To do its job, your water filter should be correctly chosen with your ponds volume and stocking level in mind, whilst also taking into consideration future fish growth. Decent pond filters for koi carp are able to rid your pond of solid waste and debris whilst also efficiently removing ammonia and other toxins. A quality pond filter will create a clear, healthy and comfortable environment for your koi carp.
The right diet and feeding methods
What you feed your koi carp, like any pet, has a huge effect on their health and longevity. Koi carp will eat both meat and vegetable products, which adds to how easy they are to keep, and they’ll sometimes feed right out of your hand! Quality koi carp fish food should promote health, growth and colour; and include vitamins, proteins and carbohydrates. Don’t feed them goldfish flakes or bread bits, but you can treat them to foods like peas, lettuce and tiny chunks of melon every now and then.
In winter, feed your koi carp a low protein wheatgerm food and switch to a high protein growth diet during the summer months. Koi carp digestive systems significantly slow down in cooler temperatures and overall digestion is much worse, so giving your fish too much food during winter means that food stays in their guts longer than is healthy, which could make them ill.
It’s worth noting that overfeeding koi carp is much easier than underfeeding them, and this is a common mistake among koi carp keepers. Remember, more food equals more solid waste and ammonia, which means poorer water conditions over time. A good rule to follow: if there’s food floating on the surface after a one minute of feeding, then you’re giving your koi carp too much.
Maintain excellent koi pond equipment
Good koi carp keeping relies almost entirely on good koi carp pond equipment. The better the pond gear you choose, the healthier your koi carp will be and the less chance you’ll have of needing to pay extra to correct future issues.
- Quality filtration system – to clean the water and remove waste and other toxins.
- Strong water pump – to circulate the pond water through the filter system.
- Pond skimmer – to remove leaves, pollen and other floating debris.
- Aeration system – ensures good oxygen levels and circulation.
- UV clarifier – to eliminate green water algae.
Protect from predators
Even in urban areas, your koi carp might be at risk from predators. Large and brightly-coloured, they’re a target for a range of animals including: cats, otters, herons, and mink. So, place a net over your pond’s surface if you think there’s a chance your fish could be harmed.
One of the main points to consider when keeping koi carp is getting the right sized pond. If you pack too many koi carp into your pond, they’ll have less space to swim, which is their main hobby, and there’ll be a more concentrated level of harmful toxins.
As a rule of thumb when keeping koi carp you should stick to ten gallons of water for every inch of fish, with a minimum water volume of 1000 gallons and a minimum pond depth of 3ft.
Not only do small ponds physically limit the comfort of your koi carp, but they’re also much harder to maintain. Little ponds have a less stable water chemistry. They’re more susceptible to rapid changes when it comes to temperature and cleanliness, becoming hotter and colder more rapidly and accumulating ammonia and nitrite at a higher rate. Just think: the greater the volume of water, the more stable the environment.
Koi carp can grow very quickly, so you should bear this in mind when thinking of how many you want in your pond.
Observe your koi carp
A sure-fire way to make sure your koi carp stay healthy is to simply check on them. Some koi carp aren’t afraid to swim at the surface and take food from your hands, while others routinely stay at the bottom of the pond and are shy feeders. Over time, you’ll notice how each fish behaves differently from the next, which will help you pick up on any problems.
Things to look out for if you’re concerned about a koi carp:
- Not eating
- Visibly injured
- Change in colour
- Consistently swimming alone
- Lethargic behaviour
- Clamped fins
- Swollen areas
- Raised scales
If you notice any of these signs, try and examine your fish and check for the following:
- Underside for damage and lesions
- Gills for damage and discolouration (should be plum or burgundy shade with no frayed edges)
- Erratic gill motion for signs of oxygen deficiency
- Scales for signs of reddening (should also be smooth and not raised)
Observing changes in the look and behaviour of your fish is a quick, simple and free-of-charge koi carp keeping method to ensure healthy pets.
Easy and effective koi carp keeping boils down to providing a good diet, optimum water conditions and quality pond equipment. Make sure their pond is big enough to allow them to swim freely, and keep checking on them and their water conditions to guarantee they have a good and long life.