Number of Fish in a Pond

JP08

Note: Duplicate post - originally in the Gardening Thread, but on reflection may be better here ...

Got a small pond, actually a holding tank with some timber cladding. 1.6m by 1.0m by 60cm deep. So only about 1000 litres. With a continuous running fountain / UV / filter - one of those Hoselock Easyclear 3000 All-In-One things.

Two fish from the old pond went in, bog standard goldfish about 10cm long. They're now best part of twice that and live with 4 10cm offspring.

Until the other day that's what we thought anyhow - now there are suddenly visible a lot (double figures) of babies in there. Some of them a good 5cm in length.

So the simple question is how many fish are too many for the pond? Or should I just not worry as long as they are all active and interested in eating.

Had a good search on the Net. There appears to be as many answers as there are websites that match the search.

Froglet

Yes,when people start adding more fish to a pond,they forget that they start breeding at an early age,and never stop.I've learnt the hard way,that's why I'm on my fourth very big,pond! Have you got any neighbours or friends who would like a few babies and have the space?


If not you have 2 options,make a larger pond for them all,but the problem will obviously arise again.Or be tough with yourself and cull a few each year.The adults will eat some,but with plants and weed in the pond,some will survive each year.I now have to force myself to do this,hate it but know if not I will get bigger problems later down the line.

Sadly if you don't you will get overcrowded and then you may get water problems,which may be helped by a bigger pump/filter.

no1catman

Yes, it is a challenge - my pond is at least 1,000 gallons. At one time I didn't have many fish, - several 'gold' and a koi left by previous householder.
The koi died, lost some to a heron, but was given some 'weed' by someone who I went for advice about the heron, and yes you've guessed it had 'babies' from the weed. Next couple of years they bred - it was great seeing little fish.
Total went up to early sixties, but went down after b***** herons, the funny thing is always have seen the fish mating - no babies for the past three years at least!
When the pond was cleaned in February, at least six newts were found - they were relocated to a good home. But a couple of months ago while replanting marigolds - found three more - would they (or indeed frogs) go for fish fry?
And incidentally, have forty-five fish now.

Froglet

Yes,newts would definitely eat fish fry,they will eat anything they can get into their mouths! Glad you got them out,I have a nature pond,and before I had my current,raised pond,some newts got in to my old pond and one got sucked in to the pump,poor thing.

JP08

Thanks for the replies.

We inherited the fish when we moved in - the solicitors had to formally ask us if we were happy to take them on. Officially, there were only 3 in a 4' square raised pond.

We found a baby one when we made the new pond. Lost a couple to heron over time before we netted the pond. Now up to the position in the original post. Fortunately we've had a couple of years of no fish breeding, but this year I guess the plant life has been a little more lush and the babies have survived.

Definitely no space for another pond, or any homes to go to in the immediate vicinity. Looks like I'm going to have to monitor the situation and be cruel to be kind at some point.

Stevie_Palimo

I thought with the ponds and more so goldfish that they grow to the surroundings so if you created a larger space they would grow to suit it, Sure I have seen this somewhere but think it only applies to goldfish.

Fosterdog

Stevie_Palimo wrote: »

I thought with the ponds and more so goldfish that they grow to the surroundings so if you created a larger space they would grow to suit it, Sure I have seen this somewhere but think it only applies to goldfish.

That's not completely true, while the outer body can become stunted by lack of space the internal organs continue to grow which eventually leads to a most likely very painful existence and then death. Some people consider it great that they have had a goldfish in a bowl that has lived to 5-10 years but in reality kept in the correct conditions they live to more like 30 years.

Think of them growing to fit their space like the horrific practice of foot binding and the pain and disfiguration that goes along with it.

paddypaws101

OP could you not offer your spare fish on local Streetlife or FB pages? Local schools or parks?
It seems so sad to cull them

tanith

We have about 20 Koi and goldfish in our pond and although they do mate and we have pregnant fish as soon as the eggs are laid or the babies hatch and emerge from weeds they get eaten we haven't had any babies in 12yrs.. I often wonder how other manage to do it? A neighbour who also has several ponds says he has to separate the babies to get them past the baby stage into a different pond.

Froglet

paddypaws101 wrote: »

OP could you not offer your spare fish on local Streetlife or FB pages? Local schools or parks?
It seems so sad to cull them

I tried to do this in the early years but very few people want young goldfish if they have their own pond,as they also have the same problem.Or you get people who know nothing about caring for them properly and want to put them in small tanks.I would not subject any of mine to a lifetime of suffering like that.

It is sad to have to cull them but I only do it when first born,or remove the eggs on the weed after spawning.You need good eyesight !

JP08

Agreed, it seems very sad.

Spotting the young/eggs in the pond is practically impossible - I didn't even notice these until some of them had got to 5cm or so in length. One is even big enough to start changing colour.

From [some of] the calculators for fish length etc on line and the size of that little Hozelock pump/filter/UV beastie (which is rated for best part of three times the size of pond it is dealing with) I may have a couple of years grace - provided that there's now enough fish in there to eat all of next years offspring.

Will see how things go. Maybe I'll just feed them less.