Series of unfortunate events = sick fish

[HillfootPond]

Hello and welcome! Wow, quite a story!

So you estimated your pond at just a little over 1000 gallons. You had 20 (good-sized) fish to start out with, a sick fish or 2, then you added more fish? I hope that you have underestimated the size of your pond, because if not, you might be overstocked. And it sounds like you added the new fish without quarantining them first.

Just MHO, but don’t assume that it’s the sludge that was causing the problem. The fish that were there for those years seemed to have done well and adapted. It sounds more like a combination of issues, and I wonder if you were trying to fix too many things at one time which messed with the balance of the pond’s ecosystem.

For now, just take things one “problem”at a time. Other than treating the sick fish, don’t worry about trying to fix anything else for now. Make sure your water is filtered and clean, and that you have a lot of water movement in the pond. Do you have an aerator to add bubbles?

Of the 20 fish only 3 are about 12” then there’s about 5 which are about 8-10” the new introductions were 2 which are 3” and 2 were 5” the rest are all little sprats of about 1-2” which we assume are the production of spawning last summer which we knew nothing about.
I’m not sure it’s overstocked! ‍ You can see the biggest ones here at the top

And we were assured by the koi specialist that they had been quarantined by them and followed the instructions they gave for introducing them to the pond. So we did the best we could with the information we had been given. ‍

 

[HillfootPond]

Welcome, your fish do not appear to be too large, if getting a 100G stock tank is difficult, try a 40-50G tote you can find in the department stores. They are not very strong but if you lead one side on the something stationary and brace the other side with sand bag it will hold water well for a temporary hospital. Have a few together to keep the fish comfortable. Make sure you have aeration and a means to clean the water if possible.

Thank you for this, I will look into it

 

[Tula]

Thanks so much for your help... how much is partial? I hope to have my husband clean off the sponges in the filter again tonight and then he could let some water out and replenish then too. 1/3??

I don't want to steer you in the wrong direction and as I'm conservative, I'd replace only 10- 20 % of the water volume at a time, letting your water tests be your guide....that means if your tests show the presence of ammonia , do a water change.

Just looked at the picture of your pond and it's lovely, looks like a formal koi pond, Water movement, via an aerator or pump ( or both ) is a big help in maintaining water quality and fish health.

 

[HillfootPond]

I don't want to steer you in the wrong direction and as I'm conservative, I'd replace only 10- 20 % of the water volume at a time, letting your water tests be your guide....that means if your tests show the presence of ammonia , do a water change.

Just looked at the picture of your pond and it's lovely, looks like a formal koi pond, Water movement, via an aerator or pump ( or both ) is a big help in maintaining water quality and fish health.

Thanks - I will ask at the koi supplier tomorrow about aeration as only have a pump to the filter but that comes back down into the pond via a little waterfall and I don’t know if this is adequate in terms of incorporating O2 into the water. We now know the owner of the house previous to the lady we bought it off constructed the pond - and he still keeps Koi in his new house (he still lives in the village) - so I assume he built it especially to keep koi.

 

[HillfootPond]

This was Magic Mike - the fish that vanished after I noticed his pectoral fins had all but gone. - looking at his caudal fin, does anybody have an opinion on whether he already had a degree of ‘fin rot’ and might therefore have been the source of bacteria into the pond.??? This was what he looked like on day of purchase back in April this year.

 

[Tula]

I can't tell from the picture. As @Mmathis said earlier, the original fish seemed to have adapted fairly well to the pond, even if it was neglected over time so it's possible the new fish introduced something to your existing fish. Also stirring up the muck for removal, could have been stressful to the fish and their immune systems were stressed, therefore making them more susceptible to things ( bacteria - parasites ) that always exist in the water.

Keep us posted and good luck.

 

[HillfootPond]

Hi guys, thank you to all those who took the time to give me advice, it was very much appreciated.
This morning we emptied out approx 10% of the pond water and then refilled. ( just added 10mls of the pond safe liquid mentioned below)
Both the black carp and orange and white goldfish were still alive this morning and I managed to isolate them into a 40litre trug - the biggest thing I’ve got right now. As you can see it it’s suspended in the pond to keep the temp of the water as even as possible. It’s now covered in a laundry bag to act as a sun reflector and to keep them concealed hopefully as calm as possible. Whilst they’ve been in there I went and sort advice from the koi specialist and they said if I were wanting to do a further course of antibiotics I’d have to wait a week or so before doing that. As I want to show my daughter (who is very concerned about these two) that I’m doing as much as possible, I’ve bought some topical medication.
So far I’ve added 2mls of Tetra pond aqua safe ‘makes tap water safe for pond fish’ as that’s what I worked out was appropriate for 40l of water. Let that settle in then I added 200g of API pond salt to make it a ‘short-term’ salt bath as a disease treatment in case the cause of the abrasions was parasitic. They were in there for ten minutes. Then I changed out the water to normal pond water.

I’m about to attempt to apply ‘propolis wound seal’ to their open wounds though it’s probably too little too late. Has anyone used this before, or have any tips on how to do this ?? It’s by NT labs and a liquid that makes a ‘waxy seal’ on contact with the water.

The plan after this is to move the trug and position under a newly purchased fountain to aerate the water in there, then should I keep them isolated in the trug over night and add a lower dose of the pond salt to hopefully reduce the water retention??

 

[Mmathis]

Both fish look pine-coned. I hope they do OK.

 

[HillfootPond]

*update.
Both the dropsy fish were treated with propolis and put back into the pond. we weren’t able to get the crappy fountain to work so I didn’t want them to suffocate in the isolation trug. Plus if they haven’t got long left on this mortal coil, I’d rather them spend their last few days with pals.