Firstly .......... huge apologies for only coming here when I have a problem. Some of you may remember that the koi are actually my other half's babies and not mine but as he is not pc "capable", here I am again. I must say, it looks very posh now

Basically, we have two ponds. One is large and deep and contains koi. The smaller pond (about 1,500 gallons I think) contains a mixture of koi, goldfish etc together with the odd lily. Both ponds have UV's, filters etc. Whilst our large koi in the bigger pond eat like there's no tomorrow, we have noticed that the fish in the smaller pond appear quiet and without much appetite. It has been like this for well over a year now. We wondered whether something was leaching into the water and therefore emptied the pond out, repainted with pond paint and filled it again. For a day or two, the fish seemed to be more active but soon reverted to their old behaviour. The fish all look well, no marks at all, no gasping etc in fact recently they looked like they were mating and last year they produced babies. All water parameters have been checked and are fine. They don't look unwell, they just aren't "busy" like our larger fish. We're not sure what to do now and I wondered whether an overhanging yew could cause any problems? Any other ideas?

If there was someone local with a microscope they would be able to see if you had any parasites. Sometimes comes with a cost, but worth it in the long run if there is one there, means you can treat it, although having a mixed pond might make it difficult.

Hope there is someone you can call, if all isn't well

Dawn

apologies accepted thou it brings a warm feeling inside to know that you trust the advise from this site and return when you have a problem. Returning members are always welcome for whatever the reason.

i am lead to believe the Yew (American, English, Japanese) Needles, seeds are on list of possible poisonous plants to koi.

the fish seemed to be more active but soon reverted to their old behavior

where the fish acting like normal [feeding etc] when you changed the pond or where they still not feeding ?
sometimes smaller fish don't feed like larger fish this is because they would be more acceptable to being taken by predators and act a little safer minded.
it is every hard to tell without in-depth tests , if the yew is causing problems in your water thou if it has been there for over a year im sure it would have had its way with your pond and you would have no fish in there.
a possible solution could just simply be to do small water changes say 20% every month .
see how you go with your first change and let us know how you and the fish get on. oh and the hubby

I don't know if it changes your views but perhaps I should give a bit more information. I was in a bit of a rush when first posting.

As I mentioned before, there are mixed fish in the small pond, including a couple of tench, two koi of about 7" and a couple of what I think are crucian carp (not sure of spelling) plus the little brown babies. They have all seemed quite sluggish for over a year. Over this weekend, someone asked if we would take some fish from them as they had difficulties and we agreed to put them in our small pond to give them a home. We saw these fish in their original pond and they seemed quite lively. However on getting them home we noticed that one had a wound on its side. We went to our local pond centre and got some ulcer/wound treatment. We did a one third water change with dechlorinater and added the treatment. We fed the fish within an hour of putting them in the pond and all the new fish were straight up for the food. The guy that gave us the fish could not afford to feed them so I assumed they were pretty hungry. However, the new fish are also now sluggish and not eating well. They're not all small fish, some are probably 6/7" long.

There is obviously something wrong with our water. If I can borrow a microscope, would I be able to see anything? Would it be worth treating the water for parasites anyway? If so, with what? We haven't seen the fish flashing at all. Their skin looks clear although I appreciate that not all parasites would be visible or cause marks. I'm not totally convinced it is the yew bush because it has been there for 20 years. I feel guilty for putting the new fish in the pond now

your filters will not yet be up to speed with the new additions and the change in water ph etc will also have an affect. common mistake for keepers to make is to feed to much food after introducing new fish causing the filter system to work even harder.
if you can get a scope you need it to have at least 200x mag
here is a guide to a scrape
doing-a-scrape-t459.html
and this is a few of the things your looking for
topic251.html
topic249.html
skin-and-gill-flukes-t247.html
ichthyobodo-costia-t248.html

if you find any come back and i will let you know what to treat with

Thanks for that. I'll let you know how I get on.

Well, we did another water change after digging out the overhanging yew. We went from this:-



To this:-



I'm pleased to say that the fish seem to have settled down and are now eating, even the two existing koi. We haven't treated for parasites as we can't see any of them flashing. Is it normal to treat for parasites even if there is no evidence of them?

Wow, the two ponds don't look the same at all. Big difference.

I would say hold off on the parasite treatment. Especially as they aren't flashing. Watch them carefully over the next week and see how they get on, carry on as you are doing improving the water quality and it should settle, fingers crossed.

Lovely pond by the way...

Dawn

Thanks Dawn. OH is a landscaper so he's got no excuse really. It was never built as a pond for koi and we only ever wanted goldfish in it. Trouble is, we inherited a few koi 20 odd years ago which grew and grew so we had to build another larger, deeper pond to accommodate them. You know how it goes

dottysue nice pond no matter how big a pond you have you always want one bigger