Yeah my tanks are filtered so I don't have any problem with a film on the top. I had both before but when I decided to cycle my tanks I went to using just Stresscoat. Course I only have two bettas, if I had a bunch in smaller/uncycled containers I might go back to using both. Fortunately I was able to keep myself from getting in too deep (for me personally anyway ) and just stuck to my two. I've had them since March 2005.