I have an oily film on top of my 5 gallon. The rest of the water is crystal clear. I do a 50 % water change about twice a week and it will go away for about 2 days and then it comes back. Any idea what it could be, or how I could get rid of it?
Livestock: Halfmoon Betta, Zebra Nerite Snail (happened previous to introduction of Zebra Nerite so I know its not him)
Equipment: I have 2 filters, a whisper 3i and a whisper 10i. Black sand substrate, a zebra rock(at least that's what they called it at the pet store.) and 25w filter. I've washed everything thoroughly with warm water before putting it in the tank so I don't think its oil from the items...
Plants: I currently have 2 Anubias and 1 Java fern.
Chemicals: I've been using topfin betta conditioner and seachem flourish. I also use a teaspoon of aquarium salt during the 50% water change.
Food: Top fin Betta pellets and, Aqueon Freeze dried blood worms(I've been very careful not to overfeed)