Hello all! I just recently got a new crown blue male betta fish about a week ago, and shortly upgraded to a 2.5 gallon kritter keepers tank on the advice of several members of the forum. I got a heater (water stays around 78 degrees ferinheight), a plastic plant, and a Petco Asian gazebo thingy for my fish to hide in. I've changed 50% of his water about every other day, using tap water that's been chlorine neutralized. His water has low nitrate and nitrite levels, about 7.8 pH, and otherwise seems fine.
However, two days ago I gave him a break from feeding to allow his digestive system to clear out, and two days later, he is still not eating any pellets. Also, there is some gross looking film-like substance on the top of the water, that I thought was natural bacteria, but is very persistently clumping together near the top and on the sides of the tank (even after 50% water changes). My betta also blows a lot of bubbles out of his gills and mouth every now and then, but I thought that he was just happy and making a little bubble nest.
Is this all normal? Or should I be worried about any one of the three aforementioned thing? Any help would be greatly appreciated! Thank you!