How many inches per year do koi grow?

Question

I want to get some koi for my indoor tank, but want to know how many inches per year they grow so I can sort out how long I have before they need to go out into a pond. I know a great deal about Koi, but no one can ever tell me their growth rate. I know goldfish do about 6 inches a year, because I breed them, but other then that I haven't a clue as to growth rate of koi!

Thanks in advance :)

My current tank is 4 foot by 15 inches by 19 inches, but I wont be getting the koi until my 6 foot by 2 foot by 2 foot is finished being built which will be later this year or next summer.

Current tank is nearly 4 foot (short by an inch or so - Jewul can't make a normal sized tank if they tried) by 15 inch by 20 inch. The pond will be 6 foot by 6 foot by 4 or so feet tall, will be square to fit into a crap back yard and above ground, filters have yet to be decided, but here is the volume specs:

Dimensions : 183 x 183 x 122cm/72" x 72" x 48
Surface area: 3.35 sqm/36.06 sq ft/ inches sq in
Volume: 4072 l./897 gal. (1075.71 US gal.)
Probable volume: 3665 l./807 gal. (968 US gal.)

I will probably have 2 or so koi and my non breeding goldfish kept in it. Will be outdoor but covered under a clear plastic roof with mesh over the actual pond.

(I went and properly measured the tank this time instead of using the website specs, so its a bit different, sorry :P)

Answer 1

there is no exact answer.. growth is gonna depend on a lot of things... for example, what you're feeding them and how clean you keep the tank. Food with low nutrient content will slow down their growth while poor quality water will cause them to allocate more energy into staying healthy rather than growing... genes also play a role but you can not determine that unless you know the parents of your stock... also keep in mind that growth slows as they get older....

under optimum conditions (depending on age) Koi can grow over an inch per month or faster.

I'll put a site that has some Koi growth rate charts for you int he sources section.

I guess an important question would be what size your indoor tank is? The smaller it is, the sooner you should transfer them if you want to get them as large as possible....

---edit---
your tank is currently at around 60 gallons... and your 6 foot tank sounds about 180 gallons... personally I would say that you could keep a few koi in the 180 for no more than two years before transferring... it really is up to you.... at 2 years with normal growth they should average out at about 15 inches... i'd think it'd be ok in the 180 until then.... it'd have to depend on how well you maintain it and how many koi you were planning on growing out in there... I'd say the more koi you were growing out, the less time they're in there... if it's two or three... they should be ok in the larger tank for maybe even 3-4 years... of course they'd do better in a larger pond of 500+ gallons though... but you're planning to transfer them so that should be ok...

Answer 2

Koi Growth Rate

Answer 3

RE:
How many inches per year do koi grow?
I want to get some koi for my indoor tank, but want to know how many inches per year they grow so I can sort out how long I have before they need to go out into a pond. I know a great deal about Koi, but no one can ever tell me their growth rate. I know goldfish do about 6 inches a year, because I...

Answer 4

the answer depends on many factors. But here is 2 of the major ones.

Laced in with a koi/goldfish's feces is a growth inhibiting chemical, remeber the old saying, "they grow to the size of their environment"? Well that is a survival charectoristic that is built into their system to survive in the environment they are subjected to in nature. So in general, the larger the pond/tank, the less koi you have (less fish shitting out the chemical), the more water changes you do (flushing out the chemical) the faster they will grow.

The second major factor is breed. Al koi originate from just one species. mankind has selectively breed them to have many different shapes and colors. In general the more inbred the koi has to be to keep a more exotic appearance the slower it will grow. Solid color kois like solid orangeor gold koi grow the fastest. Highly inbred koi like a azul will take longer to grow. A rough groth chart with good food, and lots of water changes will result in the following growth pattern:

8"-12" = first year
18" = 2 years
24" = 5 years
36" = 20 years

Just remeber that is for an average koi.

Answer 5

it all depends on the tank size if you have a LARGE tank then they will achieve full growth in about 24 months try this may help more