constipated sick betta

Question
Hi,
I recently have had trouble with my betta fish, he has been sick lethargic, not interested and sometimes not eating, and boyancing issues, today I noticed it looks like hes constipated which he seems to have this problem quite frequently, I do not now why I do not over feed him. I do know that salt is suppose to help, fasting never seems to help my fish, and I was wondering how much epsom to put in his aquarium in a one gallon tank? I read about 1/2 a teaspoon for one gallon tank.
Please let me know asap,
thanks!
olivia

Answer
It sounds like dropsy, and there is no cure for this, also he needs a filter and a heater and atleast a 2.5 gallon tank, you need to do a 50% water change and a 20% water change every week after that with out a filter, i am sorry.

I dont know what epson is, is it salt?
If so add according to the instructions that should be provided with it.