Thread: Planning a koi pond fed by a stream from a lake!

Hi all
I've had aquariums for years and love watching the fish but never had a koi pond... until now... I'm at the planning stage for my first pond. I am planning to use a pump to pump water from a 1.5 acre lake, over a waterfall, into a man-made stream. The stream would then run into the koi pond and a stream at the other end of the pond would take the water back to the lake. I'm thinking of using marine great stainless steel wire mesh where each stream meets the pond, so that the water can flow through, but the koi would stay in the pond.
I'm thinking of a 30,000 litre koi pond but it could be bigger. As a newbie to koi what I don't know is:
- Would this be a good home for koi, instead of using filters, UV lights, etc.? They would have a constant stream of fresh water from a lake which contains just over 12 million litres of water(!)
- How much flow should go into the pond and out again? I understand koi like a flow of water but not too much or it stresses them. Looking at the Oase Aquamax Eco Expert range they can do anything up to 44,000 litres per hour, but I guess it would be less than that in reality as the water would be pumped up by about 2.5 metres to the top of the waterfall. I want a good flow of water so the stream is making a nice sound, but also want the koi to be happy.
- Should the pond be designed so that the water flows through an edge of the pond so that the rest of the water in the pond is much calmer for the koi?
I really don't know where to get help on this. Internet searches haven't come up with anything so I thought I'd see if anyone on the forums can please help. I've attached a map which slows the existing lake and a rough sketch in the bottom left showing the planned streams and pond.
Many thanks
John

Hi mate,

Personally I would be very wary of pumping source water from a lake.

Cheers

Gaz

Is the lake crystal clear? Or murky? If it's murky, the pond will be also need its own mechanical filtration, more so that a normal pond, as you'll effectively be filtering the entire lake.
But I would think the clincher would be, treating for parasites. Koi are very susceptible to that, and you'd have to treat the entire lake. Take flukes for example, 30,000litres would be £75 per treatment X3 treatments. Calculate that out to 12,000,000 litres its £30,000 per treatment. -its just not practical.
With filtration though, it would be a great pond to keep some common/mirror carp and some sturgeon.

there are also enviroment agency issues wth a natural body of water.
if there is a water course into and out of it, or it is above 1 acre.
you would need a environment agency license to stock or remove fish from, or could face fines up to £50,000

https://www.gov.uk/guidance/permissi...from-a-fishery

hi mate,

Koi are nowhere near as hardy as other Carp species unfortunately.

cheers

Gaz

Originally Posted by Johni

Hi Alburglar
The lake is crystal clear and I have done the typical pond tests on it (nitrates, oxygen, etc., etc.) and all the results look good. I should also have mentioned there are a few common and grass carp in the lake that look after themselves (i.e. never fed or treated for anything) but are really healthy and growing quickly.
I definitely could spend £30k on treatments, but if the common and mirror carp are healthy would that mean there aren't any flukes in the lake? Is there a way I can test/check for flukes?
One last thing to mention - the lake is only fed by natural springs and rain water and is up on a hill...
Cheers
John

hi mate,

to name a few concerns:

Legislation as DTF has already advised
Pollutants - these could be significant
Ecosystem differences / imbalances
Debris
Parasites

Personally I would urge you to consider alternatives.

Cheers

Gaz

Originally Posted by Johni

Hi Gaz
Why would you be wary? Is there anything specific I should look out for?
Cheers
John

always happy to offer my advice.

Maybe consider an alternative set up or some hardier fish stock than Koi.

Cheers

Gaz

Originally Posted by Johni

Hi Gaz
Thanks for letting me know. I'm getting a few different answers so will see what everyone says and speak to a few more people like you who know a lot more about koi than I do (I've only read the book "Koi for Dummies") and then see what to do.
If it's too much of a risk - I wouldn't want the koi to suffer - I'll just end up with a little stream which will still be nice (but of course not as nice).
Cheers
John

Originally Posted by Johni

Hi Alburglar
I definitely could spend £30k on treatments, but if the common and mirror carp are healthy would that mean there aren't any flukes in the lake? Is there a way I can test/check for flukes?
John

Koi will die if you look at them funny. There will be parasites in the lake, all of the common ones, every year. Wild carp will be hardy. The koi need a lot of looking after.

Originally Posted by davethefish1

there are also enviroment agency issues wth a natural body of water.
if there is a water course into and out of it, or it is above 1 acre.
you would need a environment agency license to stock or remove fish from, or could face fines up to £50,000

https://www.gov.uk/guidance/permissi...from-a-fishery

That was the first thing I thought of, too.




Don't get me wrong, Johni, I think what you're proposing is a very nice idea, as a concept, but in real-world terms, it could be fraught with all manner of practical and legal pitfalls, a few of which have already been mentioned.

Originally Posted by Gazkoi

Originally Posted by Johni

there are a few common and grass carp in the lake that look after themselves (i.e. never fed or treated for anything) but are really healthy and growing quickly.
I definitely could spend £30k on treatments, but if the common and mirror carp are healthy would that mean there aren't any flukes in the lake? Is there a way I can test/check for flukes?
One last thing to mention - the lake is only fed by natural springs and rain water and is up on a hill...

hi mate,

Koi are nowhere near as hardy as other Carp species unfortunately.

I'm inclined to agree... far more 'in-breeding' in Koi genetics than wild carp, I would think. Can't say for certain, but I would expect koi to have far weaker immune systems than wild carp.

However, let's remember that this discussion isn't only one direction - even wild fish aren't immune to the influence of captive fish. For example, consider the widely-publicised sea-lice infestations commonly occurring in densely-stocked salmon farms, where fish are held captive within their natural habitat, but corralled together whilst free wild salmon swim nearby. One would think only the corralled fish would suffer, but it turns out that many of the free wild fish have also shown signs of increased susceptibility to sea-lice infestation. Whether this is due to there simply being larger populations of sea-lice (facilitated by the densely-populated salmon farms), or whether the waste 'run-off' (phosphates etc.) may be suppressing the immune function of free wild fish living nearby, or some other factor(s), is a complex issue, but I'm mentioning it purely to point out that an existing population of 'wild' carp in a lake might, conceivably, face health risks from a koi pond sharing the same water, just as the koi might face health risks from the wild carp.

Something else springs to mind: many medications (especially those for parasites) need to be used at a certain dosage in order to be effective. Alburglar's already mentioned this in relation to crazy costs, and let's be honest, no one is likely to consistently buy enough medication to treat the whole lake, even if they're a millionaire with enough money to burn. Failure to achieve the necessary dosage may lead not just to failure of the treatment on that occasion, but, potentially, to un-killed parasites becoming resistant to the medication.
One could try periodically isolating the pond from the lake, in order to treat only the captive pond water (not very logical to then allow lake water back in after treatment, but humour me, just to make a point). Imagine a scenario where a lake and a pond share the same water (and thus the same water-borne parasites). Because koi are so vulnerable to parasites, the pond is periodically treated to keep the koi relatively free from parasites, but in the scenario of crazy lake medication costs being cut here & there, or in the scenario of isolating the pond for seperate treatment, and then re-linking the pond to the lake, the lake could receive insufficient strength of treatment, and the parasite population living in the lake could thus be periodically exposed to weak medication which could lead to medication-resistance in some of those parasites, which could be bad news for the lake and the pond, and all the various fish living therein.






......and we haven't even discussed the topic of KHV.

Originally Posted by Johni

Also the lake isn't connected to any other watercourses. I'd effectively be making the lake slightly bigger with water flowing out of it and back into it again.

Originally Posted by Johni

the lake is only fed by natural springs and rain water and is up on a hill...

@Johni - you said the lake is fed by a spring - so, if it has this in-flow, can you clarify how/where the lake out-flows? Surely it's not just evaporating any water gained from the spring?

Also, will you have access to a legitimate sewer, for your ponds waste water, or are you planning on all your pond waste (including spent medicated water) being circulated back into the lake?

Well, I don't like to see anyone's dreams squashed. I'm sure that wasn't anyone's intention in this thread. Just trying to steer you away from a whole heap of possible problems that could turn your initial version of the dream into a nightmare, which would be a shame.

Could you have an ordinary closed system for your pond (i.e. completely independent of, and never connected to, the lake)?

In other words, do you have access to mains water supply and sewer network, like most houses in the UK, or is your intended pond site 'off the grid'?


A lot can be accomplished with a closed system, even including a man-made stream, but in order to make practical suggestions, we need to know what amenities you have available to you at your location.