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Dr. B.
Dr. B., Board Certified Veterinarian
Category: Vet
Satisfied Customers: 22422
Experience:  General practice veterinary surgeon with extensive experience in a wide range of species.
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I have koi carp one has been laying on the bottom for days

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Hi I have koi carp one has been laying on the bottom for days hardly eating if at all when she does eat she/he frantically swims round getting the odd bit of food the retreats back to the bottom occassionally doing a 360 turn belly up the back down another fish has started the 360 ocassionally the others seem lathargic we had a workman fall through and break our vortex so had to buy a new nexus 320 the among a is at I think 0.25 the nitrite is at I think 0.25 possibly 0.50 I've added live bacteria and later added pure pond to the nexus 320 to assist but levels still the same I've carried out approx 30% water change the pond man who fitted the nexus had an accident with the pipe and I lost approx 3ft of water pond hold 5000 gallons approx I have periodically stopped feeding them but no one says for how long so started feeding but less my pond is around 18ft x 8ft x 5ft deep I've already lost 1 fish to I think swim bladder they all appear to be periodically rushing through water as though trying to itch I have 1 think 19 fish left one being a small gold fish please can you advise the other fish is now laying on the bottom with the other one I have a pond man who says he will do a scrape and possibly antibiotics but that was Thursday he hasn't come back I'm really worried about the fish. Regards Sharon

Hello & welcome, I am Dr. B, a licensed veterinarian and I would like to help you with your wee ones today.

Is it the ammonia that is 0.25? What is the nitrate reading?

Have you re-tested this since the water change?

Does the koi have any lesions on its skin? Any red/inflamed vessels in its skin or fins?

Can you confirm she can swim upright but is laying on her back?

What aeration do you have for this pond?

Customer: replied 1 year ago.
Ammonia is 0.25 Nitrite is 0.25 possibly bordering 0.50 I check water every day it was 2.0 after the water loss but has now com down but static as above can't see any lesions or red inflamed vessels in skin or fins she can swim upright and is NOT laying on her back she is laying on her belly
Customer: replied 1 year ago.
I have a pump that goes through the nexus and a large fountain and a underwater inlet for more airation

Thank you,

Since you didn't clarify the nitrate level (this is different from nitrite and more toxic to fish), I assume you don't have a test that checks that. And I have to say that not being able to check that is very worrisome. This is because while their rapid swimming and irritation is characteristic of ammonia burns (or parasites), but bottom sitting after rapid swimming is suggestive of nitrate poisoning. When nitrates are elevated in a pond they bind the fish's red blood cells to prevent oxygen uptake. They reduce activity to reduce oxygen need but quickly "tire" and run out of oxygen when moving. In severe cases, the can develop the bends and will appear curled up and possible die.

In this case, you would be best to get a test that checks nitrates or take a sample to the local aquarium shop for testing. If the water has been static in its levels, you need to aim for a 50% change over 24 hours until you get that level down. Otherwise, you may want to see if your local pet shop has a nitrate binder. Of course, keep up on adding the nitrogen digesting bacterial supplements but this will bind nitrate so it is not poisoning the fish.

Overall, if the fish have no lesions or vasculitis and more than one fish is now affected, we'd be most worried about issues with these water parameters or parasites. So, its good that fella is coming on Thursday (sooner would be ideal of course) but antibiotics may not be te way forward. In any case, we need to cover these bases to make sure we are ruling out the water issues playing a role here.

Kind regards,

Dr. B.


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Customer: replied 1 year ago.
The NITRATES are 40ppm the FELLA is not coming Thursday he CAME Thursday gone and said he would be back and never did I have tests for ph nitrate nitrite and ammonia I test regularly that's why I only gave you the Nitrite and Ammonia readings as they are the ones I'm concerned about. My other worry is you don't appear to be reading my emais/text properly. As your asking the questions I've either already answered or saying the fella is coming when he isn't

Thank you for clarifying,

When you said "he will do a scrape," the future tense led me to think he was coming back (your initial typos and lack of regular punctuation makes your messages difficult to read). Anyway if the Nitrates are 40ppm, you have a nitrate toxicity situation and need to address it as I noted above. Plus the ammonia levels are a worry with the flashing, but addressing one will sort the other.

Take care,

Dr. B.

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