Problem with tank

Question
Hey David,
I have a problem with my tank. I set up ma 3 Gallon tank about 1 and a half months ago with one male Betta fish inside. After he got settled in about a month after i got him i noticed some white, cotton, stringy things hanging from my ornaments and fake plants, the fish doesn't seem to mind. I was wondering if it had to do with anything with my filter cartridge i mean i haven't changed it in 2 months and looks pretty dirty. Please i have no idea what it is and am trying to get rid of it.

All help would be appreciated thanks.

Answer
Hello Ismail:  The white stringy stuff is probably algae in an extreme case it could be a stand of protein.  I would change the filter cartridge monthly... as the active carbon stops absorbing after it has been wet for about 30 days... so basically after a month its like not having a filter in your tank and that could lead to free floating proteins and other issues.  If the white strand is just algae then you can take the rocks out and scrub them down with a stiff brush ... do not use soap or any other kind of cleaner on them as they will either make your fish very sick or kill it.... dave