I'm looking to purchase a nano sponge filter for my 5 gallon tank. We had a tetra whisper hob filter and it tore my betta's tail and fins up really badly. He seems to be doing okay, but I'm overhauling everything to make sure he doesn't get hurt again. I've seen some reviews that a coarse sponge can snag and tear delicate fins. This is my first fish and I'm completely clueless. I've seen other sponge filters with softer sponges for sale on other sites, but I'd really like to buy through aquarium co-op since they seem trustworthy. Does anyone have any advice/experience/suggestions for this dilemma?
