My betta fish is really ill.?

I can see the whits spots quite clearly on your Betta especially on the tail your betta has ich and fin and tail rot your tank conditions will be the cause you do need to get a test kit and test for ammonia and nitrite putting him in Fresh water was not the best thing to do either that will stress him out even more and make it worse

You need to treat him for the Ich and the fungus the fin and tail rot now i have never had a disease in my tank in the 8 years i have had fish there are many treatments out there you would need to check at your local aquatic shop which is the right one and how you use it

I think he may have ick. Ick is a parasite and is seen as white spots. The white spots release new animals that fall to the bottom and then metamorphose and swim to reinfect the fish. It will eventually kill him. I would put him in a small container with a water level no more than 6". The water should also be warm (80-85 degrees) and very soft with a ph below 7. I would use vinegar to adjust the ph. There are medications you can use but this should work. Change the water and clean the container daily. That is to get the ick out and off of the bottom. That will disrupt the life cycle of the ick. While he is being treated I would break the tank down and clean it. Use no soap. Refill with fresh water and cycle without adding any chemicals. After a couple of days if he is looking better put him back into the tank after adjusting the ph. Clean all nets and any other stuff used by the infected tank. Mild bleach solution is good to clean the stuff. Rinse with mild vinegar solution to remove the bleach.

First of all, Betta's are fighting fish, so you always need to be careful when introducing them in a new environment with other fish. It doesn't always work.

Regarding the sickness, it sounds like your Betta may have ick.

Attached, below is some more information on ick and how to prevent it.

I have attached another page with a product that you may want to try to solve the problem. Note that if your fish has had ick for an extended period of time, it is probably too late, but still worth a try.

This product is available at any pet store. Our success rate of recovery for our betta's that have gotten ick is about 50%, but the sooner, the better,

you're putting water medical care interior the water to boot, not purely leaving it out, top? in case you at the instant are not, then they are in all probability loss of life from poison from chloramine and heavy metals.