Betta Fish Problem

Question
I have a male betta, approx. 1 year old. The past few days he's been laying at the bottom of tank leaning.  Also lays on top of fake plant towards top of tank (saw that at night). He still has good appetite, swims fast to top of tank and retrieves pellet food (I'm only giving him 1 - 2 pellets per day, as always).  He seems to be using his flippers in a faster manner to get to the top to eat than usual.  He swims around a little while and then back to the bottom in a lean position.  One of his tails looks a bit shredded, maybe a little fin rot?  For almost a year, I used tap water, kept in a gallon water bottle, set out overnight first.  Past two weeks, we're in a different home, different water district.  I did the same as always.  He's in a 5" x 4" rectangular tank, no filter.  I called a local pet shop, they told me to change water immediately and put BettaSafe water conditioner drops in, which I did. Another person said I should add a 1/2 tsp of Kosher salt.  Haven't done that yet.  The Kosher salt I have is 'coarse' and I'm not sure how to dissolve it properly before adding it to his tank.  Any help you could provide would be greatly appreciated.  Thank you.

Answer
Debbie,

 First off that fish needs to be in something bigger. It is not good to keep ANYTHING in something so small. Even through you are letting the water sit out for 24 hours you still need to add a conditioner to the water. Please DO NOT put that much salt in that container. It is too much and you will burn your fish. I cannot even begin to understand the feelings of your fish in such an inappropriate home. Please, they need to be in 5 gallon aquariums all by themselves. Unless you get your fish into the right size home, he will continue to be ill. If you cannot provide everything your fish needs which include a real tank, a heater, a sponge filter, see if your fish store will take him off your hands. It is very important to do as much research as possible when thinking about getting a pet, and fish are no exception. The smallest container they can be is 2.5 gallons. If you can get him that and add a heater, since he is a tropical fish and needs his water to be between 80 and 82 degrees, you will see a big difference in your Betta. Just because the pet stores say that a Betta can be in such a small container, which is 100% untrue, does NOT make it right. I hope you are at least doing 100% water changes daily. Your fish is telling you he is not happy. And the salt has to be aquarium salt but there is no way I can tell you how much to put in that tiny cup of a home. But, to answer the question on how to administer the salt. You have to dissolve it in water completely before you add it to his water. I like to tell people that the fish in that small of a home is like up trying to live in a water heater closet. I know that this is coming to you sounding very harsh but I am a Betta breeder and they are such beautiful majestic creatures that deserve to be 100% happy and healthy. I will tell you how to give him a salt water bath. This has always helped my Betta's when they get a little ill. The instructions are below. Please, think about getting him the right size house and all the things he needs so that he can continue to be a joy in your life and very happy.


SALT WATER BATH (DIP):

 Get a container that can hold 1 gallon of water the same temp as the tank water. Add 1 teaspoon of aquarium salt that has been dissolved before adding your fish to that water. If you don't dissolve it first it can burn your fish. Let him swim in this water for 5 minutes the first day, both times, 10 minutes the second day, both times and 15 minutes the third day and every day after for 5 days. watching him closely the entire time he is in there. I want you to watch him in case he starts to have a problem, you can remove him from the salt water immediately. I would do this 2 times a day, but never in the same water. Always make fresh salt water every time you put him in.