Can’t get rid of Cotton fin fungus

[Genxredhead]

Hello! I’ve got a peppered corydora that has had cotton fin disease for about 8 weeks now. I can’t seem to get her healed all the way and would appreciate advice.

I have a 20 gallon hex tank that I started last Oct. This Cory was added in Nov of 2021.

At first I thought it was ich (I’m in my first year with an aquarium) but that was not it. Then I tried Kanaplex but that also did nothing. I finally realized it was cotton fin and started API Pimaflex.

That seems to get the ‘cotton ball’ to fall off after 5-7 days but then it grows back again less than a week later. At its best, the fin is all white and looks like a bone. That white fin never has gone away in 8 weeks time. I think I did 2 full weeks of Pimaflex then a week off with no treatment and then another 5 days or so.

I do a 25-30% water change every 7 days. I take the carbon out while treating the tank.

I’ve added aquarium salts as well, about the time I started the Kavaplex. The other 3 corys are all fine and the 2 Black Phantom Tetras are also fine.

I don’t have a quarantine tank and would like to avoid getting one if possible.

I’d appreciate help with this ‘long term’ issue. Thanks!

PS Trying again with pics....at this point in the "cycle" the fluffy white is gone and all you see is the white bone/fin

 

[Genxredhead]

Here’s a pic

 

[Colin_T]

Hi and welcome to the forum

I can't tell anything from the pictures. you need to use white light above the tank, not blue. And check the pictures on a computer before posting them to ensure they are in focus and clearly show the issue.

How much salt did you add and how long was the salt in the water?

 

[Genxredhead]

Thanks! I had not been putting salt in beforehand so I did 1 tablespoon per 5 gallons initially and now every water change I add 1.5 tablespoons.

 

[Colin_T]

DIRECTIONS FOR USING SALT TO TREAT FISH.

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.

If 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.

 

[FranciscoB]

This has only marginally relation with the current fungal problem, which is not shown well in the photos. However, one other item to consider is that the substratum shown (large gravel) is not conducive to cories long-term health. Sand or sand/mulm mixture would be more suitable, and would make easier to maintain the tank free of inocula of fungus/bacteria.

 

[Genxredhead]

DIRECTIONS FOR USING SALT TO TREAT FISH.

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.

If 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.

Wow! Thank you so much for taking time to spell all this out! I’ve already got some salt in the tank so I think I’ll start with the water changes to give them all a break and to make sure I don’t do too much salt or too long.

 

[Genxredhead]

This has only marginally relation with the current fungal problem, which is not shown well in the photos. However, one other item to consider is that the substratum shown (large gravel) is not conducive to cories long-term health. Sand or sand/mulm mixture would be more suitable, and would make easier to maintain the tank free of inocula of fungus/bacteria.

Thank you. Do you have advice on how I change out the substratum in an already established tank?

 

[Beastije]

Not sure how with this width of gravel, but with sand and others i just siphon it out with hose during water change and then put in the new washed sand.
Or scope it out with a dustpan (plastic one ofcourse)
Just beware that by removing the gravel you rise a lot of ammonia. Would be better to remove fish in a bucket first, remove plants, remove gravel, add sand and do a 95% water change and

 

[Alice B]

Thank you. Do you have advice on how I change out the substratum in an already established tank?

I remove the fish to a safe bucket of tankwater before removing gravel or even sand, just safer. Whatever kind of filter you use do not change the media at the same time as you remove the gravel. And do smaller water change on gravel removal day

 

[Valkyrie_Lips]

I remove the fish to a safe bucket of tankwater before removing gravel or even sand, just safer. Whatever kind of filter you use do not change the media at the same time as you remove the gravel. And do smaller water change on gravel removal day

This, but I would do a really good gravel vac a few days before removing the gravel. There can be a lot of gunk trapped in the deeper layers and I find giving it a good vacuum before changing the substrate helps minimize the mess.

Also, one shouldn't be changing their filter media anyway, so I would add don't rinse/clean your filter media for at least 2 weeks after the change.

OP as long as your tank is well established you shouldn't cause any spikes or have cycling issues.