Sick Cory Help!

[ProxyProne]

(12/23) I noticed a very small white bump on one of my corys head's about a week ago. Took some pictures and decided to wait and see, as he was still acting normal and I wasn't sure it was ick. (12/26) Skip forward to when I get home from Christmas, he has 2 more white spots and now I'm convinced it's ick. He is still eating/moving normally, though a little more skittish. Went to the store same day, picked up some Seachem Paraguard (only thing available) and have been treating since then. (1/1) Today he looks considerably worse. The white spots are tearing/peeling off and he is very sluggish & pale. He also has red marks on his belly (internal bleeding?).
He is the only sick fish. He has a couple of deformities & is quite a bit smaller than my other corys, which I figure contributed to the illness. I was so sure this was ick, but now I have no idea. At this point, I don't have high confidence that he is going to pull through, though he still ate with his buddies earlier today

Tank info: 5 month old 20g, 74F, planted, cycled with established sponge filter, 20% weekly water changes, 3 corys & 3 females endlers, api liquid test today: 0 ammonia, 0 nitrite, 10-20 nitrate
I know I should have a bigger group of corys. I initially got 3 because the tank was newly cycled and I didn't want to overload the bacteria. I went back to the lfs the next week and was told they wouldn't be stocking that species (false networks) anymore. Been looking for someone else who has them, but have had no luck. I regret not picking a more common species.

12/23 1 white spot on forehead + his noticeable deformities

12/23 Same spot - front view + suspicious flat white spot on nose

12/26 2 spots right behind gills + forehead spot is bigger

1/1 No new growths since treating, but old ones peeling + pale + red spotting

 

[Colin_T]

Hi and welcome to the forum

It is not white spot.

The red is blood from bacteria damaging the tissue.

The white bits appear to be excess mucous covering injured areas of skin.

The fish is a bit skinny, which could mean intestinal worms or gill flukes, or both. This might be a contributing factor but not the underlying cause of the problem. We can deal with worms and gill flukes in a few weeks time if the fish survives.

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The gravel looks dirty. Do you use a gravel cleaner when you do water changes?

How often and how do you clean the filter?

What do you feed them and how often do you feed them?


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WHAT TO DO NOW?
Stop adding the medication, it only works on external protozoan parasites and is not helping.

Wipe the inside of the glass down with a clean fish sponge. This removes the biofilm on the glass and the biofilm will contain lots of harmful bacteria, fungus, protozoans and various other microscopic life forms.

Do a 75% water change and gravel clean the substrate every day for a week. The water changes and gravel cleaning will reduce the number of disease organisms in the water and provide a cleaner environment for the fish to recover in. It also removes a lot of the gunk and this means any medication can work on treating the fish instead of being wasted killing the pathogens in the gunk.
Make sure any new water is free of chlorine/ chloramine before it is added to the tank.

Clean the filter if it hasn't been done in the last 2 weeks. Wash the filter materials/ media in a bucket of tank water and re-use them. Tip the bucket of dirty water on the garden/ lawn. Cleaning the filter means less gunk and cleaner water with fewer pathogens.

Increase surface turbulence/ aeration when you have sick fish, or when using salt or medications because they reduce the dissolved oxygen in the water.

Add some salt, (see directions below).

If there's no improvement after a couple of big water changes, gravel cleaning the substrate, and adding salt, post more pictures.


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SALT
You can add rock salt (often sold as aquarium salt) or swimming pool salt to the aquarium at the dose rate of 1 heaped tablespoon per 20 litres of water. If there is no improvement after 48 hours you can double that dose rate so there is 2 heaped tablespoons of salt per 20 litres.

Keep the salt level like this for at least 2 weeks but no longer than 4 weeks otherwise kidney damage can occur. Kidney damage is more likely to occur in fish from soft water (tetras, Corydoras, angelfish, Bettas & gouramis, loaches) that are exposed to high levels of salt for an extended period of time, and is not an issue with livebearers, rainbowfish or other salt tolerant species.

The salt will not affect the beneficial filter bacteria, fish, plants, shrimp or snails.

After you use salt and the fish have recovered, you do a 10% water change each day for a week using only fresh water that has been dechlorinated. Then do a 20% water change each day for a week. Then you can do bigger water changes after that. This dilutes the salt out of the tank slowly so it doesn't harm the fish.

When you do water changes while using salt, you need to treat the new water with salt before adding it to the tank. This will keep the salt level stable in the tank and minimise stress on the fish.

When you first add salt, add the salt to a small bucket of tank water and dissolve the salt. Then slowly pour the salt water into the tank near the filter outlet. Add the salt over a couple of minutes.

 

[itiwhetu]

Do you know what pH is in this tank.

 

[ProxyProne]

Do you know what pH is in this tank.

Yeah. Its a constant 8.0 same as the lfs I got the fish from.

 

[itiwhetu]

Yeah. Its a constant 8.0 same as the lfs I got the fish from.

This is just too high for Cory's to be happy, they like acid/soft water. I think your problems all stem from your pH. Freshwater fish prefer acid tanks in general.

 

[ProxyProne]

The gravel looks dirty. Do you use a gravel cleaner when you do water changes?

Yes! It's actually sand & fluval stratum. It looks quite a bit worse in those photos and it was the day before cleaning day.

How often and how do you clean the filter?

Every week during the water change. I rinse it out in the water from the tank.

What do you feed them and how often do you feed them?

6 days a week rotating: frozen bloodworm, frozen brine shrimp, omega 1 flakes & catfish pellets. I try my best to get them a little bit of everything.

Thank you for all the info! I will pick up some salt tomorrow and start adding based on your recommendations + the additional water changes & cleanings. Is 74F an okay temp to treat them at or should I raise it? I hope the little guy makes it. He's actually perked up a little since I made the original post.

 

[Colin_T]

The temperature is fine.

Whilst the pH is a bit high for most Corydoras, it didn't cause this.

After this is over, I would deworm the aquarium. See section 3 of the following link for deworming fish.

What to do if your fish has Stringy White Poop.

Fish do a stringy white poop for several reasons. 1) Internal Bacterial Infections causes the fish to stop eating, swell up like a balloon, breath heavily at the surface or near a filter outlet, do stringy white poop, and die within 24-48 hours of showing these symptoms. This cannot normally be...

www.fishforums.net

 

[itiwhetu]

The temperature is fine.

Whilst the pH is a bit high for most Corydoras, it didn't cause this.

After this is over, I would deworm the aquarium. See section 3 of the following link for deworming fish.

What to do if your fish has Stringy White Poop.

Fish do a stringy white poop for several reasons. 1) Internal Bacterial Infections causes the fish to stop eating, swell up like a balloon, breath heavily at the surface or near a filter outlet, do stringy white poop, and die within 24-48 hours of showing these symptoms. This cannot normally be...

www.fishforums.net

Mate, how can you be so certain that the pH isn't the underlying cause of this problem?

 

[Colin_T]

Because only 1 Corydoras has issues. If pH was the problem, then all the Cories would be showing some sort of issue, maybe not as bad as the one in the picture, but they all or most of them should be showing some symptoms.

The pH might be a contributing factor but there is something else wrong with the fish (internally) and it has the external problems too. The fish might have worms or gill flukes or just has internal problems from being injured while young, or maybe a genetic disorder, and this could be weakening it, making it more susceptible to other issues. Then add a high pH, maybe dirty substrate, not digesting food properly, and you get a weak fish. It might even be old, and that would weaken it too.