Originally Posted by MaggieLynn
frozen peas? and i do have a filter but its too strong of a current so i need to get a different one, right now i dont have it on but i just moved him from a 1 gallon to a 5 gallon tank today so the water is pretty fresh
It isn't advisable to use peas with bettas. Epsom salt is for constipation and is much safer than peas. For a 5 gal tank, you should do a 50% water change every week.
Sorry about your girl :( The "film" you saw is protein. There isn't much you can do about it except use something like a bubbler or a filter to disturb the surface of the water. It isn't particularly bad or unhealthy and it just depends on the water you use. I don't believe there is a specific cause, it just builds up in stagnate water...