Cloudy Film On Waters Surface?

Just when I thought things were getting better....

A film has developed on the waters surface of my (filtered and heated) 5 gallon tank - home to one betta fish. (He *looks* like he’s doing okay but I’m hesitant to say that). A week or so ago, I had this cloudy transparent slimy film develop on top of my tank. I thought it was from an essential oil diffuser I was using nearby on the same desk, and so I emptied the tank completely, cleaned everything, added fresh water, cleaned the sponge in the filter, and popped my fish and all his decor back in.... today it’s back! There’s no scent and my fish doesn’t seem super bothered by ... but what do I know! I don’t have a clue what the cause is, but when I dip my hand in and try to clean it up, the film gathers in slimy pieces on either side of the tank. I have a whisper filter that has (pretty) low water pressure, but it’s never ever been like this before (I have had the filter since this July). I just want to know any suggestions so I can keep Simon safe and happy... I am so scared this is harmful for him.

 

I haven't gotten it since I have my filter but I did get it on my 2-gallon bowl and when I researched it it was a protein film

 

It's probably just bio-film. More surface agitation should help get rid of it.

 

It's quite normal but probably won't help with oxygenation of the water.
Years ago I had a skimmer attachment on my filter inlet that sucked it up, now I scoop it up with a cup (when I feel like it) and have spray bar just above the surface to help with airation.

Does anyone know if it can cause any problems?

 

It's quite normal but probably won't help with oxygenation of the water.
Years ago I had a skimmer attachment on my filter inlet that sucked it up, now I scoop it up with a cup (when I feel like it) and have spray bar just above the surface to help with airation.

Does anyone know if it can cause any problems?

It answer your question and the OP, no its not harmful to fish. While it does decrease the oxygen diffusion equation in a small marginal amount, this is not life threatening if you have good water circulation- particularly water agitation at the surface. Some fish such as bettas are use to oxygen depleted waters, and will also do fine without major water agitation.


Its mostly unsightly to us. Good way of getting rid is more water agitation - like an airstone or powerhead -; manual removal or consider getting a surface skimmer.