No question it is bacteria. Bite the bullet and get the disenfection kit from CW or somewhere else. Follow the instructions and flsuh flussh with filtered water. The blue filter for the white caannisster at CW is pretty well spectd.
You can find better spec ceramic filters, more costly on the internet. Get one with silver in the carbon bloc or other core. The silver kills bacteria. Get a new hose, one with ssilver, in it, if you can find one. there were two or three on the Internet. Be sure to flush your water heater. Never put unfiltered water in your tank.