Koi problems

[DannyK]

Thanks for your comments.
All tests for me aok but got a new toy, an inhalor.
Not so the fish. It succumbed yesterday. Fished it out and photographed it. Just got to try to get photos on site as Flckr still playing up.
I shall double check my measurements. The flow may be overstated as the intake end of pipe is several feet from filter. I shall also see if I can see any of the "new" fish. There's so much vegetation and duck weed.
Thank you for your comments.
The filter has three (?) horizontal layers of sponge. The base has what look like plastic hair-rollers in it and I added more from an old Hozelock filter. I may have overpumped as I thought it was important to keep water oxygenated.
Thanks for your comments so far

[DannyK]

Was having a look for spec of filter but looks as if discontinued. Thinking about it, I am sure I would not have exceeded the flow rate specified for it.

Will have sit down this afternoon and try yet again to post photos.

[burnie]

The problem with water passing through a filter too quickly is the filter will only be able to remove solid particles, the bacteria in the filter will not be able to remove the nitrates.

[DannyK]

At last Flckr settled down.

No sign of the new Koi but they were small and there is plenty of vegetation for them to hide in.

Did get water tested at Woodcote and they said it was ok. He suggested treating pond with Medifin before restocking.

I am thinking of slowing down water flow by fitting a T and a tap in the hose.

I do have a 30 watt UV filter but decommissioned months ago it as the fitting design was poor and giving problems.

I am thinking of replacing the filter as it is so difficult to clean. The old Hozelock one was good but they don't do parts for it now. https://www.flickr.com/photos/103667076@N05/shares/k53865https://www.flickr.com/photos/103667.../shares/30d6NY

[burnie]

Having large koi(they will grow large if they are not already) in a pond with plants and trying to filter it could be fraught with problems, weed clogging your filters and intake being one. Most koi keepers keep the fish in clean ponds that can be vacuumed regularly, if you want a natural pond with plants, I would recommend other fish species and keep the fish stocking levels low and not bother with a filter.

[SarrissUK]

As far as I know, koi will eat all your plants with no exceptions, and their poo is very potent and will poison the water quite quickly, so you need a very strong filter. That's it - that's the extent of my knowledge of koi

[DannyK]

Thanks folks.

The pump cage does get clogged up quite frequently.

Would goldfish be ok with all the vegetation? Won't restock until next year.

[burnie]

There are a lot of ornamental fish that you could have in a planted pond, if you plan to keep a filter going you can have more fish in as well, it's just that large, expensive koi can be both destructive and temperamental to keep alive.
If it were my pond I would go for un filtered, your pond surface area is quite large for oxygen exchange and with some additional plants like milfoil or hornwort you should be able to have a decent number of modest sized fish. With no splashing water from a pump/filter, you can shelter the surface with lily plants, this will reduce any green algae and with the addition of some live daphnia, you can keep on top of the water quality and feed the fish at the same time. Remember not to over feed fish, it is almost impossible to starve a fish in a pond, but it is quite easy to pollute the pond by having un eaten food in the water. I used to have the following types of fish:-
Tench are a great fish for cleaning up the bottom of ponds, they will come to the surface to feed on floating food too and are good at keeping midge and mosquito larvae numbers down.
Gold fish are a cyprinid, similar to koi, but do not grow so large and are relatively hardy, with your pond only 2 feet deep, you have to factor in over winter temperatures.
Do not buy Sturgeon to put in a pond with weed and no water flow, they will just die.
There are some species listed here for example, I found on googling.
https://www.gardensite.co.uk/aquatics/pond-fish/
Orfe can be delicate, so better avoided and grass carp grow too large, shubunkins and comets are ideal, you may see some of the "bubble headed" varieties and really long tailed/finned ones, these are more for keeping in tanks in the house rather than in a garden and can be prone to disease problems. Finally of course there are some native varieties, best not to catch your own though as you might bring in disease. I have in the past kept most British natives, even a Pike once in it's own little pond.

[Jungle Jane]

You can get filters that sit outside the pond,we used to have one years ago a bit like this in the link but it was square & you can put plants/rockery around to hide it,we used to have the filter outlet hose fill up a small bird bath area at the top of the fountain & the water spilled down some fountain rockery into the main pond where the fish were,we had a couple of ghost koi but a heron got one,then my dad planted so many plants you couldn’t really see the fish,they like hiding areas ~

https://www.allpondsolutions.co.uk/1...8aAv3TEALw_wcB

[DannyK]

Thought pond was a dead zone but when clearing duckweed I saw three small butterfly koi hiding under a large zantedeschia. There may be more, we shall see when things die back.

I was going to switch to goldfish until I saw butterfly koi. I think I will now go for goldfish.

Would tench go for damsel fly and dragon fly nymphs?

Got lots of large foliage plants. Yank a lot of skunk cabbages out! Try to deadhead now.
I did get rid of the flag iris as it was a thug, needing a saw to cut rhizomes! The variegated version is far better behaved. We do have herons around here.

The previous owner took his pump and filter! He assured me no pump needed but the fish were gasping on surface so I got a pump and filter. If it were me I would have had pond bigger and deeper. I keep the pump on throughout the winter for the birds.

Many thanks, I've now got some research to do.

[burnie]

To answer the Tench question the answer is if it will fit in their mouths then yes they may well eat it, not known to eat small fish though.
Regarding the pump running through the winter, it is generally accepted that you shouldn't, due to the thermocline effect, but in a 2 foot deep pond the effect may be minimal, if you can lift the extraction tube off the bottom of the pond that might do it. The theory is that the slightly warmer water at the bottom should not be mixed with the freezing water on the surface.
I am about to build a new pond in my garden, but this will be a wildlife pond, the only fish will be sticklebacks that the grandkids will hopefully help me catch.