Betta Fin Rot?

Question
QUESTION: Hello! I have a male betta that I keep in a 2.5 gallon tank that is heated to 80 degrees. About 2 months ago, he started to develop white, filmy, slimy looking strands that attach to his fins. I did some research, and I thought he may have fin rot. I immediately began to do more water changes, and his fins improved. However, this evening I noticed that there are strands developing again on his pectoral fins. I do full water changes every 6-7 days (mostly every 6), and use stress-coat and aquarium salt. I rinse everything in his tank and scrub the sides of his tank as well. I am careful not to overfeed. I did a water change 2 days ago, which is why I am surprised to see the slimy strands back. I was wondering if there is anything else that could be causing his fins to deteriorate, as I think I keep my water pretty clean (but perhaps it really isn't...)? I want to make sure he is healthy, so if you have any ideas of what I can do differently regarding his care that would be very helpful. I am going to do a full water change in the morning, so hopefully that helps! Thank you so much!

ANSWER: Hi Hannah,
This sounds like he may have columnaris disease.  There are many causes to columnaris, and the main one is "Stress"  Also a lack of minerals may cause columnaris.  Always use tap water, and never bottled water.   If detected early, the fish may be cured completely.  It is a terrible disease, and should not be taken lightly.  Treat him with a combination of Kanamycin, and Furan-2.   Columnaris is a gram negative bacterial disease, so you must use an antibiotic for gram negative bacterial, and not gram positive.  Many people have used "Tetracycline" with no results.  If it is a mild case of Columnaris, 'Triple Sulpha" may help in the early stages, but I would go with kanamcycin combined with furan-2.  Add 11/2 teaspoons of diluted aquarium salt to your water.  Columnaris does not live in salty water, so this may help eliminate this terrible disease.
You may read all about columaris on this site:  http://www.americanaquariumproducts.com/Columnaris.html
I hope this will help.
Lynda

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QUESTION: Thank you so much for all your help, Lynda! Now when you say diluted aquarium salt, what exactly does that refer to? I have API brand aquarium salt, but it does not say "diluted" anywhere. I have asked at the pet store before, and they were not knowledgeable as to what diluted aquarium salt was. Will it be ok to put the 1.5 teaspoons of my salt in my betta's 2.5 gallon tank to help with the columnaris, or do I need to do something to make the salt diluted? Thank you so much!

Answer
Hi Hannah,
Diluted means mixing the aquarium salt that you have with water from the tank, until the mixture looks clear.  We should never put salt in the tank without diluting it first.  Just take a glass of water from your tank, and mix the salt in it, then slowly pour the water back into the tank.
Lynda