Slimy Film In Tank??

I have one male Betta Fish that I keep in a 2.5 gallon tank with a heater, moss ball, and various other fake soft plants. I do 50% water changes each week. But I noticed that the very top of the tank develops a slimy film after a few days or so. My little guy seems just fine, he’s very active and eating his food like usual. I’ve read that it develops when the water is still? Is that it? Or is it something to be concerned about? I’m new to this and just want to be sure!

 

I think one of the main causes for that slimy film is overfeeding your fish. It's called protein film. I'd recommend getting a filter for your tank too! Don't get any filter though because betta fish have a hard time swimming with a filter with a harsh current going through their water. The link below is a great filter because you can adjust the power of the filter. The filter will break up the film, but won't treat it.

Tetra Whisper Internal Power Filter with BioScrubber for Aquariums

 

I think one of the main causes for that slimy film is overfeeding your fish. It's called protein film. I'd recommend getting a filter for your tank too! Don't get any filter though because betta fish have a hard time swimming with a filter with a harsh current going through their water. The link below is a great filter because you can adjust the power of the filter. The filter will break up the film, but won't treat it.

Tetra Whisper Internal Power Filter with BioScrubber for Aquariums

Thank you for your response! So, is it harmless, then? I definitely want to get rid of it, but just want to be sure

 

Any body of water with anything organic in it will get that film if the water's surface isn't getting broken up at all. It's a layer of microorganisms called biofilm. It's actually coating everything in the tank, it's just much more visible on the water's surface. (If you have shrimp or snails, it's actually an important part of their diet.) It builds up on all my betta tanks because their filters are so low flow; it's harmless but a little unsightly. I get rid of most of it by dragging a paper towel over the surface before I feed them every day. You can also run an airstone to break the surface tension of the water.

 

Any body of water with anything organic in it will get that film if the water's surface isn't getting broken up at all. It's a layer of microorganisms called biofilm. It's actually coating everything in the tank, it's just much more visible on the water's surface. (If you have shrimp or snails, it's actually an important part of their diet.) It builds up on all my betta tanks because their filters are so low flow; it's harmless but a little unsightly. I get rid of most of it by dragging a paper towel over the surface before I feed them every day. You can also run an airstone to break the surface tension of the water.

Thank you!! I plan to get some air stones today