Fungus on castle?

[OrkyBetta]

there is this whitish film/stringy crud on my castle in my betta tank. It is slimy. How do I get rid of this? Is it a fungus?

 

[Tokis-Phoenix]

Probably, usually a sign you are over feeding your fish a bit too much or not cleaning the tank ornements enough; i would just plonk the castle in some very hot water and clean the growth off and that should kill it off.