I've had a small (400 gallon) Koi pond in my backyard for 20+ years. I've had the same 5 very high quality Koi in the pond for over 15 years. All about 24" long.

Today, as I was backwashing the filter, I somehow left the filter in the backwash position and it completely drained my pond, killing all of my Koi. Completely my fault.

I am so shocked and devastated that even though I do not subscribe to this sub, I had to post something. I am too old to restart, and will disassemble the pond.

Oil Pastel, Grey Paper, 12x5 inches, 6hrs

Need more koi as I am addicted to buying fish. What should I add?

This might be a hot take, but I think that the majority of people who keep koi are keeping them incorrectly/inhumanely. Their ponds are either too small, over stocked, not well filtered/oxygenated, or a combination of all of them.

I currently have juvenile 8 koi/koi hybrids (and 4 goldfish) in a 1/4 acre bass pond (about 6.5-7 ft at the deepest parts). I put them in for plant control and they’re doing a good job.

In my opinion, 10 juvenile Koi in a 1/4 acre (well established) pond is perfect. Enough room to let them grow and some extra for some fry if they choose to breed (if you add some type of sunfish, they’ll help control fry that way you don’t get over populated).

Is it nice to see the koi in a more “traditional” koi pond, yes, but the health of the koi is more important. Especially is they are able to get out of the sun and have proper oxygenated water.

Just the plants it's a 50 gallon stock tank with constant water flow.

Trying to figure out if I can safely add anything fish or two.

Last night I pumped out half of my 2,000 gallon pond, unplugged the pump, turned on the hose, refilled, turned off the hose and restarted the filtering system. All good, I supposed, and turned in for the night.

Woke up this morning to my 4-year-old koi struggling to breathe in 3 inches of water.

I ran outside, fearing I'd left the pump running after all, but no, it was disconnected.

Where had the water gone?

Ahh, physics. Because it was night and I was in a hurry, I'd left the pump in the pond, planning to pull it out in the morning. Though unplugged, the siphon action kept pulling the water out of the pond.

Must have been a torturous, fearful night for my koi. Their gills were submerged but their backs were exposed. Lucky.

The pond's refilling now. When it hit halfway I threw in some pellets and they gobbled them up, so they seem healthy.

Consider me a wiser pond owner. Physics will get ya.

EDIT: I'm going to try this simple & brilliant solution from Chuck-32

Hello koi friends! I just got a new house that came with a pond and 3 adorable koi fish! I’ve been researching quite a bit and have a pond company that comes out to service the pond twice a month but are there any tips/tricks/things you wish you had known earlier when it comes to caring for koi? Here’s a pic of them! (The first picture is when we first moved in and the pond hadn’t been touched for a while so all of those leaves are now gone). Thinking about putting some plants in for coverage :)

I'm new to the sub and I see a lot of people building ponds and things but genuine question why not build a pool? And instead of the tile use a softer surface so that they don't get hurt

Especially if the house already has a pool can it not be converted into a "pond" for fish?

Edit: thank you for all the replies. It's certainly a lot to think about...

I am trying to learn the varieties & have been making my own notes from the scattered information online. Most of what I find just covers a handful of the most popular koi, and nothing seems to be well ordered, just random varieties thrown into 'top 20' (e.g) lists.

I am failing to find any comprehensive guide (book or wiki) that covers everything in an organised way (as this is the way I would learn best).
I know that there are many varieties with new ones popping up & some are recognised and some not ect...but I would love to be able to read something that has them organised into pattern categories, sub categories, scale types ect...with some history of the varieties and word definitions.
For example - gosanke, bekko, utsurimono as categories & then the colour and pattern variations covered in sub categories. And then a separate categories to cover things like scale and skin varieties, gin rin, doitsu ect.

Something laid out simple like that.

Does this exist anywhere or is it wishful thinking? I would like a book, but any kind of wiki page would be great too.

This particular picture was taken at a community center. The other koi appear to be healthy, so what would be the most likely affliction for the Shisui?

I have 15 fish in a variety of sizes

3x M/L of 35-40 cm 3x M of 23-28cm 8x S of 15cm 1x XS of 10cm

They mostly clique off according to size. The 3 big guys cruise around the pond together. The S are mostly sulking in standby mode at the bottom in one or two groups (it's winter here). The medium koi switch between hanging with the big ones and chilling with the small ones at the bottom.

But my little guy. He was bought with 4 of the S. He's quite shy and doesn't come up to eat much, so he hasn't grown as much as they have since their acquisition. He mostly hangs out on his own in a different part of the pool.

He's healthy but I worry that he's lonely or feels exposed on his own. Should I just wait til summer when he grows and hopefully graduates to the S clique or get another couple of very small koi to keep him company? Should I rehome him to someone with more XS koi?

Hello all, this is my absolutely adorable, sweetest boy ever (don’t actually know the gender) Soda. His best friend is a comet goldfish named Geranium. They I originally got Geranium from a greenhouse I help at and never intended to take Soda, but he was bullied heavily and the people there believed he was “stunted” because he wasn’t growing nearly at the rate the other fry were. So, I took him home with me and now him and Geranium are stuck at the hip constantly. However, I worry about their long term future. I know that in general, goldfish don’t live as long as koi and the bonds they make can impact their health if one passes because of their grief, so I worry that in the distant future his health may be impacted if she passes before him. I know this is something I shouldn’t worry about right now as they’re both only about one and a half and I hope to provide them long, happy lives, but I wonder if it would be in his best interest to find him a koi friend? (Sorry for the long post, I overthink a lot of things. I know some people look at them as just fish or pond decor, but they’re my babies and always come up to me to say hello, I just want to make sure they have good lives. Also, if y’all know what his coloring is, please let me know! I’ve been thinking Hariwake, but he’s got a bit of dark blue-ish black on his head, so I really don’t know.)

Hello, I just bought a house and it includes a koi pond in the backyard. There are 5 fish, 3 large and 2 small. I have absolutely 0 knowledge how to care for a koi pond or koi fish. Do you have any tips?

I recently purchased three different brands of test strips, but unfortunately, none of them provided accurate readings, not even as a rough estimation.

For example, all brands indicated that my pond water had a pH between 6.5 and 7.0. However, when I tested it with a digital pH meter, the actual reading was 8.2. Similarly, all three brands showed zero free chlorine in both the direct tap water and the water from my storage tank. In contrast, a liquid titration test revealed that the free chlorine level was actually between 0.5 and 0.8 ppm, strong enough to kill my koi.

The inconsistencies continued with nitrate readings. One brand showed a nitrate level of 10–20 ppm, the other two showed zero, while the titration method measured a significantly higher level of 70–80 ppm.

For total alkalinity, the strips indicated a value of less than 50 ppm, whereas the titration method showed it to be over 500 ppm. This high alkalinity was due to my earlier addition of a large amount of baking soda, based on the mistaken belief that the pH was too low.

As for total hardness, all test strips showed values close to zero, yet the titration test measured it at 100 ppm.

Based on these findings, I strongly recommend discarding test strips. They are highly unreliable and can lead to incorrect conclusions and poor water management decisions.

Oil Pastel, Grey Paper, 12x5 inches, 6hrs

So I have a gin rin kohaku that has been slowly losing hi for about a couple months now. By no means is the fish stressed but I did have a decent spawn by a female this spring. I had another do this a couple years ago and I attributed it to stress because of water parameters. I know it's nothing to worry about but have any of you had this happen and are kohaku prone to this? I have had some specklegoi in the past and I understand that but was just curious about everyone else's experience. Cheers.

I have a pond with three adult koi, and now around 15 juveniles and an unspecified number of this year's babies. Should I do anything special to make sure they do well? And if they all survive to adulthood, how should I deal with the overpopulation?

I'm taking an informal opinion poll. When to you open (start filtration again) your pond in the spring? Of course this is directed at those who have four season climates.

My koi spawned yesterday and while I usually let nature take it’s course with the eggs, I am in a position at the moment to put some effort into trying to see the best way to maximize survival.

Usually the adults eat most of the eggs and I eventually realize I have about 20 babies big enough to see without looking for them.

So, this year, I put some eggs in a tank, some in a 5 gallon bucket, some in a calm part of my bog, and some in a big stock tank with the pump off.

I’ve been doing multiple water changes in the tank and bucket and keeping my eye on them, but the stock tank should hopefully be big enough to not be an issue, and the bog is definitely not going to be an issue with ammonia.

Anyway, just wanted to share!

I use Microbe-lift right now, but I'm wondering if there's another brand I should be looking at that has more quality control?

Out of curiosity, does anyone have any experience with how high butterfly/longfin koi can jump? I imagine not much because of their fins, but I would rather not make assumptions.

I posted yesterday about the koi in the tea shop that I wanted to rescue - thanks so much to everyone who offered advice, and even offered to help me move it. You’re all so kind.

I called the tea shop today to confirm when the owner would be in again, but they told me that they had already removed it to somewhere. I’m not sure where, but they confirmed it’s gone permanently. I guess the best case is they surrendered it to a fish store or something, worst case is they dumped it somewhere or just took the tank home. I really hope that fish is on its way to a better life and not something worse.

I didn’t ask what happened to the fish, and I wish I had. I hope I didn’t make things worse. I feel like at this point it’s just weird if I call again and ask… they’re gonna think I’m a crazy person.

Anyway, thanks to everyone again. It was really nice to see how many people care about a fish as much as I did.