So I inherited a pond as we move house. Instructions were do nothing except sprinkle a handful of Koi food each evening, measuring by what they don’t eat.

Recently I’ve observed some odd behaviours which I wouldn’t mind a comment on if possible;

a) Fish lying on their sides, on top of the pond plant, yet swimming away?
b) All the fish at the top of the pond every day “gulping” at the surface – whats that about?

I found 2 dead fish this morning. A Gold fish, floating and now almost white with white eyes. A black fish, turning beige no other discolouring.

Am I doing something wrong, is a) and b) symptomatic of a problem?

Was the beige on the underside? (if so probably always there you just didn’t see before)

How were the fins, any white spots or marks or shredding.

Whats the water like? clear cloudy smell at all?

Was the white fish just changed colour smoothly, or was a white substance on it?

The fish which are still there, are there fins (dorsal mainly) up firmly most of the time, or are they down flat on their back (a sign of sickness)

Is there a pump? do you freshen the water often?

You need to check the water PH, Nitrates and Nitrites balance, does the pond have a water filter system, i would suggest a trip to a pond/ fish dealer shop and get a testing kit also i would do an 80% water change immediatly until you know what the issue is(test the old water first)
Gulping is a sign of collapsed oxygen in the water as is flashing / jumping and lethargy a koi pond is a labour of love and takes a lot of time. , a Goldfish pond is a lot easier to deal with so long term ic you havent the time sell the big fish on and buy some hardy little ones

TBH, they could be goldfish, they are no bigger than the size of my hand (from bottom of palm to tip of middle finger), except most are black.

We have pond / fish place up the road so I’ll get the kit. The plant life / algae has expanded a lot lately.

The previous owners though said they never did anything at all for 5 / 7 years. There’s no filters, waterfalls or such like.

Fish on the surface often on their sides can be a sign of swim bladder infection or the start of other problems – dropsy can cause it too. Do they seem to swim ok or does it look like they are struggling to swim properly?
Could also be that there isn’t enough oxygen in the water so they are coming to the surface to gasp for air.

If it’s dropsy, then they will start to get bloated & their scales will look like pine cones. Their eyes bulge too.

I inherited a pond and it is a pain in the butt too be honest. I managed to get rid of the bigger fish, and still need to get rid of the smaller ones – about 15 fish ranging from 4-12″ i suppose. We have got a pump with waterfall to aerate the pond, if there is a lot of pondweed in the water then scoop it out.

I’d go to your local fish shop & explain the situation. They should help with what you need to do, but you might end up spending a fair bit of cash to get a few bits & pieces…

Just back from the pond/fish place. Stumpy, the dead fish (nor the live ones I’ve seen) show those signs.

Apparantly I’m not the only one thats visited with this issue. Choice are to aerate the pond with a pump (£70), remove some weeds, or (not necessary recommended), churn up the water with the garden hose once a day – of course there’s a chlorine issue there.

He did say its a combo of the humid weather, plus probably the “lifetime of the pond” ie the fish/plants have grown to a size where oxygen is at a premium. His view was unless there’s a money issue, de clutter the pond and let nature take its course.

:-/

Probably the best bet , if you have an old paddling pool ( you can get one for a fiver) tranfer the fish and water to pool while you drain it and give it a good clear out put fresh water back in from the tap and get some water conditioner to take out or make safe any chemicals like chlorine
Dont go and spend 70 quid on a aeriator and air brick look on ebay and gumtree for someone selling one or better still think about some type of small pump and a mini waterfall to aeriate the water for next year.
Plants are good for a pond ( not koi as they pull them to bits) but too many and the oxygen collapses at night

You have not mentioned filtration? Does your pond have any?

Also what size and depth is the pond and roughly how many and what size fish do you think you have?

My guess, it could be a combo of things, overstocking, lack of filtration, over feeding, etc.

First step for me, would be getting a sample of the water tested.

I’ve seen 6/7 fish I think, the biggest 6 or 7 inches, the rest about 4-5 inches. There’s no filtration its just a 6ft by 4.5ft square pond, about 2ft deep.

I think a 4.5ft Sq 2ft deep pond will be overstocked with 6 fish at 5 inches.

I’ve got a 6ftx6ft 3ft deep pond – about twice the volume and have 6 goldfish about 3 or 4 inches long. I have a cheap air pump and two air stones to aerate it and a filter running the water through foam. Other than cleaning the filter every so often it’s maintenance free.

I think the warmer the water the less oxygen it holds. The shallower the pond the faster it warms up. Dead leaves and other organic matter decaying also uses up oxygen.

So, as suggested above I’d try transferring the fish and draining and cleaning the pond. Then refill and treat water and see how it goes. Maybe see if you could give away a couple of the larger fish.

Air pumps are cheap and pretty trouble free. For example

http://www.ebay.co.uk/itm/BLAGDON-PA2-FISH-POND-AIR-PUMP-GARDEN-WATER-AIRPUMP-KIT-/160774315803?pt=UK_HomeGarden_Garden_PondsWaterFeatures_UK&hash=item256ee55f1b

Filtration will be your savour but only if it the right one for your pond.

Take a jar of your pond water to your local aquatic outlet and ask them to test it also take photo’s of ypur pond along as well.

Then take a 2nd & 3rd sample of water to other aquatic outlets because the most important thing I’ve learnt working in the aquatic trade for 25 years (Jesus is it really that long?) is that there are no experts in this industry and no two ponds will ever be the same

Koi and goldfish are very ‘dirty’ fish as irc mentions its sounds like you are over stocked and some form of filtration will help.

I was told many years ago by a neighbour who had an amazing Koi pond and got me started on collecting fish.

‘its all about how you look after the water’

Hope they are feeling better since you last posted btw.

Well, I removed the dead fish and a dying plant, and “churned” the water with the garden hose as advised over the weekend.

This morning there were less fish gulping, and those that were seemed to do it for 20 seconds then return underwater rather than staying at the top.

I think with the cooler weather today also it help, hopefully all will be OK.