Water change mistake - please help

[whatacooldog]

My sister has a freshwater tank and was wanting to treat her betta who has finrot so I recommended aquarium salt in a water change. Unfortunately in the water change she forgot to include the stress coat water conditioner. This means she put in a water change of unconditioned water treated with an amount of aquarium salt intended for the size of tank she has. They appear to be in shock and aren't moving much. The water change was done two and a half to three hours ago, the fish were noticed in their condition 30 minutes ago.

These fish have since been moved to an emergency tank situation (bowl we treated with API stress coat and seachem stability as there's no backup tank ready) from the tank. She has since added the stress coat and stability to her full tank but it was well after the initial change. What needs to be done for the fish and for the tank? They're not moving very much. ):

Tank parameters:
5.5 gal
Temp: 78 degrees F
Fish include one adult male betta and two julie corydora catfish, one boy and one girl.

 

[mcordelia]

make absolutely sure that you did the right dosing on the salt and the dechlorinator, if in doubt, do a 75+% water change in the main tank and then re-dose (remember, there will be some salt in the water already, so be careful you don't add too much salt). Corydoras catfish are salt-sensitive I believe(@NCaquatics can give you more details), so you may need to do half of the recommended salt dose. If the bowl does not have filtration or aeration, your best bet is to get the fish back into their regular tank once you have figured out the water situation. If the bowl has come down in temperature, I recommend using some type of gradual acclimation method when putting them back into the main tank.

Also, I have heard that API stress coat may cause harm to betta labyrinth organ over time, so you may want to look into switching to something like seachem prime instead.

good luck, and keep us posted.

 

[CassCats]

Few things...

I'm going to suggest skipping the salt and just do daily large water changes to help the fin rot. Fin rot is usually caused by poor water conditions, however some bettas are also prone to it regardless.
But corydoras cannot handle salt, I would even avoid halving the dose of it.

I would test your water parameters, see what your ammonia, nitrite, and nitrate levels are to rule out these as the cause of the fin rot.

To combat the finrot, daily 50% water changes to keep the water pristine to reduce bacterial pathogens in the water.

Now onto other less pressing but important concerns.
A 5.5g is too small for corydoras. They need a 20g or larger and a group of 6 or more as theyre schooling fish and will be shy and stressed kept in too few of numbers. And in a small tank, theyre lacking in more places to hide as well. I would see if your sister would be willing to upgrade to a 20 gallon and get 4 more corydoras. They would be a lot happier in a larger group and tank.
Plus, that's really pushing your bioload in a 5g. It'd be easier to manage the water quality in a larger one.

 

[CassCats]

Oh. Another thought.
Is there a shop that you can get Indian almond leaves, or perhaps order some off amazon? Sometimes called catappa leaves or "betta leaves"
But the tannins would be very good for the bettas fins.