White film in my guppy tank

[Fishys]

I have a male guppy tank and theres always this coating on my decorations and its reall sticky and hard to get off any advice would be nice

 

[Fishys]

It dried Clear still sticky but clear
Also it is a male guppy tank that had a aluminium plant in it and they are silicon decoration with a hard plastic base

 

[Fishlegend]

IS it sticky to your fingers or does it like cling / stick to the décor? If it's sticking to the décor than it's biofilm most Likely