Help needed with new large fibreglass pond please

[brokensword]

Fish will grow to the size of their surroundings but know you are shortening their life span doing this. Obviously, a fish like koi that has an adult size of 3’ and is put in a 20 gallon tank won’t get 3’ long, but it also won’t live for 30 years either and in all likelihood would die in a couple years at best due to poor water quality.

In you case, putting koi in say an 6-800 gallon pond they will still try to grow to 3’ long. What will happen though is as they get bigger they will overwhelm your filter system and you will end up with dying fish before they attain that size, as well…..As for your friends ponds and their “success” with keeping koi, they are successful until they aren’t and when they aren’t they will end up losing all their fish. we have many come on here asking for help because their koi are dying in there 800 gallon pond, but have been ok for years. What is changing is the fish are getting bigger and producing more waste and this will overwhelm the ponds filter system resulting in the fish dying.

you're just too damn polite, sometimes, @Jhn ; should have just 'liked' my response instead. Glad SOMEONE spelled it out, though...

 

[Jhn]

@brokensword there I liked your response to my response.

I thought about halfway through why am I doing all this typing, should have just stopped when I saw your response. Then was like screw it, almost done anyhow.

 

[reefsr]

Hi all, again thanks for all this .. I don’t understand why you all recommend zero koi for this pond, I have several friends with smaller ponds/or about the same for years, and they all have small koi in, maybe seven to 10 inches , and have had no issues really.

don’t fish grow to the size of there surroundings…

This is the filter etc ,recommended to me

Laguna Clear-Flo 10000L Waterfall Pump & Pressure Filter Kit

Laguna Clear Flo 10000

www.lagunaponds.co.uk

also did I mention I’m from the UK, not that matters…

so this bulkhead, are they screwed into the holes and the tubing threaded through the formed hole, is this watertight ??.

I think I’ll maybe just block the holes then, and run the pipes over the top , just seems a shame as there obviously there for a reason…

can I easily get the threaded plug in for the bulkhead if I do go down that route..??

I was really considering hosetails like in the attached pics …

Thanks again all , really great stuff this…

Carl

Hi Carlos,

There's a hormone called "somatostatin" that fish will release if they deem the setup improper to live in and grow in. This limits their growth and is unhealthy for the fish, which must be what your friends fish did. Koi get much too large for that setup, and if they do stunt their growth (by releasing this hormone), that's just a sign of bad care. I would strongly urge you to not do this, as it's not looking out for the health of the fish like a good pet owner should do.

Like others suggested, I would highly recommend a few shubunkin. They have great coloration but do not get nearly as large, although they do get quite sizey themselves. You might just want to upgrade in the near future or before you start your build. The general rule of thumb for any koi is 1,000 gallons (3,785 liters) for the first koi, and 500 gallons for every additional koi.

Source: https://link.springer.com/article/10.1023/B:FISH.0000032727.75493.e8