How do I care for a Koi fish?
January 6, 2011 by KOI Section
Filed under Koi Care
Ive owned bettas before in a 10 gallon tank but I dont like how you can only own one at a time. Ive tried putting multiple females in a tank before and they got along but soon killed each other so I want to keep on owning a single betta in the tank because I love that breed of fish but I also want to begin keeping Koi fish. I know you cant keep koi in small tanks like that so I would like to get a pond in the yard for it but I want to know the basics on things. What size pond would I need to get? Do the preformed ones from garden stores work (the very large ones that are about 2 or 3 feet deep and about 6 to 9 feet around or do I need to dig out and form my own pond? What’s the best location, in the shade? how often do I clean it and how? Do I need any filtration systems or chemicals for the water? What do I feed them and how much? What do I do about winter when it gets super cold out and what depth of water should they be in for me to not worry? Basically Im a beginner and anything wi
and anything will help me so please give me advice and share your knowledge about keeping koi fish with me! Any advice or help will be greatly appreciated! <3
First, I applaud that you realize koi cannot be kept in aquarium tanks. Thank you. Koi are a relative of the goldfish, so any goldfish care and information you find can be applied to koi. Koi can grow huge; easily 2 feet. And as they can get large in girth as well, in addition to the huge amount of waste they create, they require massive amounts of water per fish. As this is a pond and permanent, you want to plan ahead for your koi growing to their largest size. As such, you are going to need to plan on about 60-75 gallons of water per one fully grown adult fish. I personally would not choose the preformed ponds vs. a liner because if you do not fill in every single gap, the preformed pond could crack when you step on it or any other type of pressure is applied. With a liner, it shapes itself to the surface underneath and is a lot more forgiving of a slightly uneven surface. Be advised that either require a sufficient layer of sand (about 2 inches) on top of the dirt under the pond. I wouldn’t put all of the pond in full sun as it may heat up the water too much in the summer as well as encourage algae growth. I would make sure that some of it at least is in the shade; however, under a tree is not a good idea as the leaves and debris from the tree will make a mess of the water both visually as well as rot and foul the water. You will need to do a good, thorough, deep down, drain the water completely cleaning about once a year, but once a week, using a pool net, scoop out sticks and leaves, and any other debris that falls into the pond. A filter such as with aquariums is not needed, but you do need circulation for water aeration. These underwater pumps do have a filter of sorts and these will need to be rinsed out weekly as well. For adequate flow, I would recommend going about two sizes higher than the pond size you have, i.e., if you have a 500 gallon pond, I would choose a pump that said it was for about a 1,500 gallon pond. Aside from treating the water you add to the pond during cleaning with a dechlorinator, I would try to stay away from chemicals as a remedy for poor water conditions. There’s nothing like hard work and dedication that makes for the healthiest pond. They make koi pellets in several different types. For spring and summer feeding, for fall and winter feeding, for color, for growth, etc. Unless you choose tiny babies to start with, avoid the growth because they do that fast enough on their own. Instead, focus on the color formulas. As for winter conditions, they need a minimum depth of 18 inches of water to survive and preferably 24 inches of water. If you have a pump circulating water, you do not need to keep a hole in the top, but if you do not, you need to constantly keep about a 12 inch hole in the surface of the water to provide oxygen. Do not feed your fish at all once the water temperature goes below around 45 degrees F. They go into a type of hibernation, even though they are still awake and swimming around and do not eat at all, so any food you provide will just fall to the bottom and rot and make the water toxic. Before you get your fish, even after you have your pond built, I would suggest doing a lot of reading about the successful care of koi so that you will raise happy, healthy koi that may live for 40-50 years. Good luck!
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Koi are wonderful fish! Although I have successfully kept very small koi in an aquarium for limited amounts of time (like, less than two years), they really do need a pond, the bigger, the better. Most people who put in ponds NEVER wish they would’ve put in a smaller one, and in fact, most people wish they would have put in a larger one. We started with a small, 500-750 gallon one, and within a year expanded to a 3,000 gallon one, which is what we have had for the last 8 years.
I do not like the pre-formed ponds. That hard plastic does not weather well – the UV rays eventually break them down and they are subject to cracks and leaks. Also, if your area freezes, the freeze/thaw cycle can cause the pre-formed ponds to “heave” themselves out of the ground. Plus, your hole has to match them *exactly* as to size, depth, and shape – much easier said than done!
Instead, I think it is much easier just to make your own. Use a hose to lay out the shape you like (if you want a curvy one – otherwise, just layout the dimensions you want). Then, dig the hole. If you want to overwinter koi outside, and you’re in an area subject to freezes, your pond should be at least three feet deep at it’s deepest point. Otherwise, you can get away with it only being 18-24″ deep (our “big side” is 10′ in diameter and about 3′ deep, the smaller side is about 6′ in diameter and 18″ deep).
Fill the hole with a 2-3″ layer of sand, then lay down some carpet pad (it makes great “underlayment” to keep the roots, etc., from puncturing/growing through your liner). Then, put down your liner – get the thickest EPDM you can afford, at least 30 mil (changing a liner is brutal, though – we put down 45 mil). Let it sit out in the sun a bit to warm up and make for easier handling. Fill the pond with water, easing the liner into place as you go – you want as few folds as possible and no wrinkles!
If you live in an area that is likely to be subject to predators such as herons, egrets, or raccoons, build the pond with sides that are straight up and down. You can put plants in on stands made of upside down milk crates, upside down buckets or tubs with holes drilled in them to let the water move through, or even on powder-coated metal stands. I’ve used all three, and find the black 3- and 5-gallon perrenial pots from the nursery to be perfect. If you are somewhere where predators are not an issue, you can go ahead and make “stepped” sides with planting shelves the way most of the books, etc., tell you to do.
Then, line your pond with whatever combination of rocks/materials you like and that look good to you. Don’t forget to put an edging of rocks on the outside of the pond (called “coping”) to keep your liner in place.
The set up I prefer is a bottom drain, attached by a hose to an external pump, which pulls pond water off the bottom of the pond and pumps it into a veggie filter, from where it trickles back into the pond. Do not skimp on a pump, either. It is better to have one too big, than too small. And be sure to get a pond pump, not a sump pump or some other type. Pond pumps are sealed, whereas other types can leak oil, etc., back into your pond (bad for your fish and plants – could even kill them).
We have had one pond where we housed our pump in a box lined with cedar that we dug into the ground, but the one we have now is in a cedar box on our nearby deck. The box looks like a bench, and can be used for seating, and is easier to access than the one in the ground. Both are great “disguises” for the ugly old pump, though.
Although many people use mechanical and UV filters to keep the water clean, I prefer a veggie filter. This is a box with baffles in it (if it is external) or a shallow, “boggy” area adjacent to the pond (if it is “internal”), designed to slow down the water flow, filled with gravel to catch sediment, and planted with a heavy feeder like water iris. We resisted going to a veggie filter until just last year, thinking that no way could something that “primitive” give the same water quality as all that technology of bead filters and UV lights, etc. However, keeping the water quality good was a constant struggle (90% of pond keeping is water keeping – take care of the water and the fish will take care of themselves!). Finally, we gave in, and put in a 500-gallon veggie filter for our 3,000 gallon pond. Our water quality has never been better! So much so, that this year we discontinued the UV and mechanical filters and are running solely off the veggie filter. Our fish have never been healthier or happier! Ideally, you should shoot to have about 15-20% of your pond volume in your veggie/bog filter.
If you choose to go with mechanical/UV filtration instead of a veggie/bog filter, get the biggest ones you can afford. Better to “over” filter, if there is such a thing. And, you will still need plants. Fish eat and create waste which combines with decayed leaves, etc., to produce ammonia, which is bad for the fish. Luckily, Mother Nature makes a bacteria that “eats” the ammonia, converting it to nitrites. Unfortunately, nitrites are also bad for fish. Mother Nature comes to the rescue again with another bacteria that converts the nitrites into nitrates, which the fish can handle OK in small quantities. Nitrates are essentially fertilizer which the plants just eat up, removing most of them from the water, leaving good, clean water for the fish to live in. A good rule of thumb is to have plants equal to about 50-60% of your water’s surface area. However, not all of these plants need to be surface plants – you should have a combination of oxygenating plants, such as anacharis (warning – larger koi will nibble at these), heavy feeders such as water iris and lillies, and surface plants that provide shade and hiding places for the fish, such as water hyacinth, water lettuce, and azolla (fairy fern).
The best location for your pond is in part shade, part sun, and away from trees. Otherwise, you will constantly be pulling/skimming leaves from it. If it is all in the sun, you may have a problem with excessive algae growth and water that is too warm for your fish. If it is all in the shade, you’ll have trouble finding plants that grow well and your fish may not grow as fast, either. If you have a little of both, the fish can regulate their own temperatures and you should get good growth of both the fish and the plants.
I have basically described to you our set up, and we do one big cleaning in the spring, is all, where we drain it down to about half and clean out all but about 5-10% of the muck that has accumulated over the previous year. The influx of new water when we fill it back up usually stimulates spawning, too. Other than that, we do about a 20% water change monthly during the summer – that’s it. You don’t want to completely tear it apart and clean it because you’ll end up killing off your beneficial bacteria. Condition your water to remove chlorine, etc., which would otherwise burn your fishes’ gills, and do not use secondary or irrigation water – it is full of all kinds of critters like flukes that can be seriously detrimental to your fishes’ health. Also, around a 3% saline level is good for their overall health and does not seem to affect the plants too much. Use pond salt or Epsom salts – any salt with no iodine. DO NOT use table salt!
Feed your koi small meals, often, of a good-quality koi pellet. Koi are basically pigs and think they are starving most of the time, but too much food in the water at once will just decay and foul your water. You can offer treats like watermelon pieces, orange slices, cucumber slices, green peas, Cheerios, shrimp, etc., on a sparing basis. Different fish like different things – ours love little bits of pizza crust and bloodworms!
Your fish will also eat more when weather is warmer than when it is colder. Right now, we are in triple digit temperatures and I am feeding mine (we have 18, ranging in size from about 6″ up to about 24″) three times a day, as much as they will eat in about 5 minutes (about 1/2 cup of BB-sized pellets). If your water temperature is below 55 degrees, you should not feed them at all – their stomachs will not process the food and it will basically rot in their guts and kill them.
Make sure your fish are fat and sassy heading into the fall, so they have a lot of stored fat to live on all winter. They will go into a hibernation-like state, hanging out on the bottom of the pond and not moving much until the water warms up again. Keep a bubbler going just enough to break the surface of the water and keep the water circulating, and put a small livestock trough heater or pond heater in to keep at least a 12″ diameter part of the pond from freezing over so that gasses, etc., have a means of escape and oxygenation of the water can occur. The only winter in which we lost fish was the year our pond heater gave out and the pond froze over, trapping the gasses under the ice and preventing oxygen from getting in. That’s why we went to the horse trough heater – heavier duty!
I like to give my fish a “shotgun” approach cure-all before the weather cools too much, too, just to make sure that the most common parasites and bacteria are killed off before the fish go into their vulnerable hibernation phase, and they won’t be too vulnerable when stressed by the cold. I prefer a combination of Praziquantel (“Prazi”) and Pro-Form C – those two will take care of most “bugs” and do not harm plants, and are readily available over the internet from places like Petco and Doctors Foster and Smith. Make sure you apply them according to directions and watch your water temperature – some of them say not to apply if the water is colder than 70 degrees or so, so you have a specific window of opportunity in which to do this.
I am happy to share any information I have with you – feel free to e-mail me through my profile. Ponding is a great hobby and I wish you the best of luck. Hope this helps!
The common carp is a hardy fish, and koi retain that durability. Koi must be kept in a 240 gallon container per fish. This means two koi would require 480 gallons of space. Koi are cold water fish, so it’s advisable to have a meter or more of depth in areas of the world that become warm during the summer. In areas that get harsh winters, it is a good idea to have a pond that is a minimum of 1.5 meters (4 1/2 feet) deep so that it won’t freeze solid. It is also a good idea to keep a space open with a bubbler and a horse trough heater.
Koi’s bright colors put them at a severe disadvantage against predators; a white-skinned Kohaku is a visual dinner bell against the dark green of a pond. Herons, kingfishers, raccoons, cats, foxes, and badgers are all capable of emptying a pond of its fish. A well-designed outdoor pond will have areas too deep for herons to stand in, overhangs high enough above the water that mammals can’t reach in, and shade trees overhead to block the view of aerial passersby. It may prove necessary to string nets or wires above the surface. The pond should include a pump and filtration system to keep the water clear. Koi are an omnivorous fish and will often eat a wide variety of foods, including peas, lettuce, and watermelon. Koi food is designed not only to be nutritionally balanced, but also to float so as to encourage them to come to the surface. When they are eating, it is possible to check them for parasites and ulcers. Koi will recognize the person feeding them and gather around at dinnertime. They can even be trained to take the food from one’s hand. Koi have been known to live in captivity in periods exceeding 100 years. And becoming 3ft-4ft in length In the winter their digestive system slows nearly to a halt, and they eat very little, perhaps no more than nibbles of algae from the bottom. Their appetite won’t come back until the water warms up in the spring. When the temperature drops below 50 degrees Fahrenheit (10 °C), feeding, particularly with protein, should be halted or the food can go rancid in their stomach causing sickness. If kept properly, koi can live about 30–40 years. Some have reportedly lived up to 200 years.
I have a koi pond i built myself 15ft x 5ft, depth are 2.5 thru 3.5 ft, shape of figure 8, consist of one big oval shape deeper than the larger oval shape which is more shallow. The deeper the pond the better they can withstand the winter. Building your own pond is rewarding and so much fun since u can shape it any way u want and as large as u want, but require lots of time. Start by buying pond lining and pump kit that includes internal pump and filter, UV light. Dig your desire shape of pond that fit lining. After, layout lining, buy bricks or stone to anchor the lining around the pond. Fill pond with water, add pond treatment (pond salt-soften water-)
and solutions to kill clorine and bacteria. Make sure pond water is not still, always have water circulating like fountain or live plants to give oxygen. After everything wait at least 8 hours before putting fish in. There are so much u need to know, i dont have time to explain all. Hopefully this will help.
Second option, buy a prebuilt pond and set it to the ground and buy a complete pond kit with everything u need.
This is going to be a long answer since I have been breeding koi for over 30 years. Your pond location should be in FULL sun not shade. One of the main reasons being koi eat plants and algae are plants. Leaves from shading trees will reak havock on your pond.
With that said, preforms from the store work great for a first pond and most come with a filter and directions. EASY! Koi ponds should never be deeper than 4 feet with the exception of 12,000 gallon ponds. the size depends on how many fish you want to keep in the pond. You can also add a few shubs and other colorful goldfish as tweeners and they will all be happy. You never have to clean your pond if you plant it properly in the begining. Remember some algae is your friend here. Water changes are not necessary unless you are having a water problem. Filter comes with the preforms usually a fountain biofiler with attachments for fountains and waterfalls. Another great idea for adding dissolved oxygen. Chemicals a good dechlor and a ecofix tinter.
Koi like goldfish have no stomachs. If you choose to feed your outdoor fish feed them a high quality food. 48% proteins and less than 5% fat. You can supplement their diet with things like Lettuce, mustard greens, turnip greens, collard greens, spinach, peas, endive, Watersprite, seaweed, cukes, kale, chard, broccoli, lima beans, green beans, etc. and feed aquatic plants (e.g. duckweed, azolla, salvenia, etc) or hair algae daily.
For their Carotenoids which are a family of pigments the fish can’t make themselves and are obtained as part of the diet. These pigments result in red, yellow and orange colors. Fish have cells called chromataphores. Those cells convert lutein and carotenes into astaxanthin which is the red pigment.
sources include, brine shrimp, krill, spirulina, marigold flowers, paprika, sweet red peppers, yams, carrots, pumpkin
Watermellons and oranges are also good as well as proteins like chicken (chicken livers) beef (livers and parts) and pork as well as worms and bugs
As far as winter care, your koi will winter happily in the pond. A few things you NEED to remember, when the water temps start hanging around 50 for the better part of the day, STOP feeding your koi. They will start their hybernation process. If you continue to feed your koi it could kill them over the winter. There are even winterizing foods to help clean the fish’s system out for hybernation.
DO NOT tap, cut or break the ice on your pond for any reason. Your fish are in hybernation and do not need excess oxygen from the water nor do they need to eat. Chopping a hole in a pond made from cement or preform will send shock waves thru the water and kill your fish. Your filter as well can be removed from the pond once you stop feeding. In the spring, once the ice is off and the water temps remain above 50 you can restart your filter and start to feed again.
I will strongly suggest you do not get a heater for your pond over winter. If you are not experienced or have the time to monitor the water temperatures, tossing in a heater isn’t going to do much for your fish or the water they are in. Unless you are living in MI or Canada 2-3 foot deep pond will work fine for your Koi.
Also, know your fish. Since they are in a pond they are more difficult to see to determine disease. However, fish kept in ponds tend to be more hearty with less diseases than aquarium fish.
You DO NOT need a UV Sterilizer. Most outdoor ponds don’t. Algae still grows and ich isn’t that big of a problem.
Remember the rain water will change the PH in your pond. Be careful when adding water to “top off” your pond. I never do. I wait for the rain to take care of it.
Get a pond test kit. (Not an aquarium kit). They are relativly inexpensive and believe it or not even the dip strips work well.
Plants that koi eat are always great. Floating Hyathis or water lettuce are great for shading the pond and keeping algae at bay. They also hid your fish from birds, coons, cats and other animals that may want to Eat them. The largest contributor of the pond eating animal are snakes. They will quietly sneek in and take what they want. Keep the rock pilings to a minimum around your pond.
DO NOT ADD salt to your pond. Salt is a no no with healthy koi and goldfish. This causes bloat in both. Also, you still need to cycle your pond like a fish tank prior to the addition of any fish.
When adding fish, especially koi one at a time a week – two weeks apart. Smaller gold fish can be added at a rate of 1″ of fish per 5 gallons of water one week apart.
Without going thru the entire run of ponds check out the web page and as always, feel free to email me whenever you need to.
http://www.pond-solutions.co.uk/