Corys look sick - what do I do?

[cobraman]

Now I have problems with two of my three peppered corys.

Got home from work and noticed one has a red eye (a red circle around its one eye) as though it had been attacked. I did the feed and he ate as normal and also moved absolutely fine. So I looked for my other two.

One is absolutely fine and looks fit and healthy but the other just doesn't move and isn't taking any food either. I usually drop pellets and they go mad for the food but he just didn't take any. However, one of my loaches nudged him and he went shooting off and then swims alongside the glass and then sat on the side of the filter (he's never done this before) and then dropped to the bottom again and just sat there.

I've checked the water and ammonia has gone up to 0.50 so I am planning a water change tonight. There also seems to be far more waste at the bottom of the tank than usual and I am wondering if I have overfed (I took stock of more fish at the weekend and fed them a little more).

Any ideas? Will a 80% water change help matters?

 

[seangee]

Definitely change the water. Reduce feeding (every other day is plenty). Also clean the substrate (I'll assume you have sand as you have Corys. Then keep testing and anytime you have ammonia or nitrite readings do a water change of 50-75%

 

[cobraman]

Thanks - just completed a 75% water change and added in tapsafe. It looks like the cory has popeye so need to somehow treat that.

 

[seangee]

Personally I would keep a close eye on him and avoid medication unless it develops an infection. Clean fresh water is the best medication for fish.

 

[Sarah73]

Any pictures of the red eye? Corydoras are very sensitive to any meds you give them as they are scale-less creatures.

 

[Byron]

I feel it prudent to mention that in two earlier threads, the mix of fish in this tank was considered to be trouble waiting to happen. Cories looking like they are being attacked, and being nudged by a loach, is not a good sign.

Stress is the direct cause of 95% of all fish disease in an aquarium. Preventing stress is therefore key to healthy fish, and that means careful stocking of species and numbers. The Red Tail Shark may very well be behind this; this is not a peaceful fish, and it can overnight become a real terror. Please take my comments as intended, wanting to help your fish.

 

[Colin_T]

Do a 75% water change and complete gravel clean each day for a week, or longer if needed.
And do a 75% water change and gravel clean any time you have any ammonia or nitrite.

The introduction of new fish will have put more load on the filter and you will need to do more water changes and gravel cleaning to compensate for the extra waste.

See how the Cory's eye looks after 3 water changes and if no improvement post a picture and we can recommend something.

 

[cobraman]

Thanks peeps.

I woke up this morning expecting to find a dead cory or two but they are still alive but still not moving much. The red eye is still there as well. I'll do daily water changes as mentioned above and have also brought a bottle of this - https://www.amazon.co.uk/dp/B001REDVAO/?tag=

Will this help matters?

 

[Colin_T]

Don't add any medication yet. Do a few water changes first and see how the fish goes.

 

[cobraman]

Thank you Colin_T

 

[cobraman]

Right - returned home from work and saw the cory floating atop the aquarium and thought it was dead. So I went to pick it up and it swam to the bottom of the tank. His eye has fallen out completely. He ate a bit and then I looked again and he is at the top of the tank resting on the black filter lopsided. I touched him again and he shot to the bottom of the aquarium and starting scavenging the sand as per usual. Should I just end his misery?

 

[Colin_T]

Has he lost his eye or is it just swollen out a lot?
Fish can live with only 1 eye but we need to figure out what is going on. If you have a loach in the tank it might have taken the eye.

I am not sure what is in the medication you posted the link to. You could try that but I would use it in a separate tank and only use at half strength for catfish.

 

[seangee]

Do you still have all your fish in together? If they are the culprit of the bullying will continue until the Corys are all dead.

 

[cobraman]

Right. The little cory passed away. And then the loaches had the other eye to eat too. Not nice viewing so I took him out straightaway and binned him.

However, the other cory who was slow moving and unwilling to eat has been absolutely fine this evening. He seems active as ever and ate loads of food and is still plodding along with the other remaining cory (who is also fine). I'm hoping it was the water that killed the cory (and not through bullying) but I did another water change tonight so hopefully this is doing the trick as all the fish are swimming as normal and eating too.

 

[Colin_T]

I don't normally keep loaches and Corydoras together because they don't naturally occur together and some loaches are very aggressive. If any more Cories have issues, remove the loach.