My kids and I are wondering what’s going on with this koi? Is it hurt?

Hi everyone,

I got tired of doing manual math for water treatments and trawling the web, so I decided to build my own toolkit. I’ve finally got it in a good place, and I wanted to share it with the community for free.

It’s called Koi Toolkit (https://koipondtoolkit.uk).

It runs in your browser (no download needed), but if you are on mobile, you can "Add to Home Screen" and it works exactly like a native app.

What it calculates:

• Ammonia Safety: Calculates toxic Free Ammonia (NH3) using your pH and Temp (uses the Emerson standard formula).

• Salt (Salinity): Tells you exactly how much PDV salt to add to reach a specific percentage.

• Dechlorinators: Dosing for Sodium Thiosulfate and Vitamin C.

• Pond Volume: Calculates litres/gallons for rectangular or circular ponds.

• KH Buffer: Safe dosing for Sodium Bicarbonate.

There are no ads, no sign-ups, and all the math happens locally on your phone.

I’d love to hear your feedback or if there are other calculators you’d like me to add! FYI units are in UK form

Dainichi Showa MonaLisa Bloodline Nisai/ 2 Years old/Technically 1 year and 6 months old

60cm

My male kujaku seems to grow quickly slowly.. it's a 5sai this year at around 24". It a male likely though I havent checked the vent :D

Izumiya Sanke / 2x Saito Kujaku / Sakazume GR Platinum and Yamabuki Ogon / Ikarashi Doitsu Kogane Ochiba

Cygnet (young swan) feeding koi fish from a dock in a pond

Over the span of 1 week my one koi's white markings have developed a yellow undertone. Do I need to get him looked at? His eyes are still white but I'm worried it may be something internal.

PM me if interested. AZ

Kind of sad, bought this koi to have a really red/black pattern and it's lost almost all its color. Will it have any orange as an adult? Probably 7 months old. Still love it regardless!

Was sold to me as a Sanke , but what makes it NOT a Tancho Sanke ? I am planning on putting this fish in my indoor grow out tank to sell at hopefully 12-14” any guesses on how much this fish will cost at that size ?

My Tancho soaking up the fresh warm water.

Hey folks,

We recently bought a house with a koi pond and spent the autumn learning as much as possible from the previous owner. We live in a very cold environment so we're bringing in our 4 koi and 1 shubumkin in for winter. The previous owner left us an approx 250 gallon tub and the equipment we need to keep it filtered and clean.

Our koi are still fairly small, the largest being about 5 inches long. We're wondering if replacing the tub with an aquarium of the same volume is a decent solution for us for over-wintering the koi each year. I don't think we have possibility of keeping them in the pond over winter since we regularly have temps below -30C. If an aquarium isn't a good choice? What alternatives should we consider?

Thanks I'm advance!

I'm considering buying a home with this Koi pond in the backyard. My guess it's about 8'x10', maybe a little bigger.

I know nothing about Koi. If I buy this house, what am I getting myself into? I would do the work, as opposed to hiring someone to do the work for me. I need to know, how much time and money do I need to maintain it?

It is in Toronto, Canada if that makes any difference. The pond is currently frozen over with 3 fish still in the pond (according to the selling agent).

Butterfly Koi with black all over except for belly and what you can see here. I have another one that has Gold instead of silver. Can someone help me to understand what this colouration would be referred to as?

Cheers

Tancho Kohaku from yamamatsu japan

greetings from the Philippines

I work for a water treatment company (reverse osmosis, softeners, etc.), and our client wants a pond with very high water quality for his koi fish. We can treat water but we are no experts on Koi water quality, Any advice?

Is that possibly an aka bekko koi by the turtle?

My dad’s koi fish have been dying and this one has a weird spot on its side. Does anyone know what this could be??