Brown Algae and White Mould - Help!

I've noticed during my last few water changes that I have brown algae attachig itself to my fake plants (I also have a few real ones which I thought might have been the culprit). After reading in here somewhere I concluded that the brown algae was not hurting my Peanut so I left it as is. When I am cleaning the tank with my syphen, I try to suck up as much of it as I can.

Tonight was tank change night again (I try to do it on the same day and around the same time each week) and I noticed my filter cartridges have white fuzzy mould on them?! My tank parameters are fine and within range. What is causing these unsightly issues and how do I get rid of them safely for my peanut? I also want to note that I promptly clean all uneaten food and waste when I see it and (s)he has not changed behaviour and is just as friendly and interactive as they were when I brought them home a few months ago.

Post some pictures, I get some brownish algae growing on the glass sometimes but its just normal. The white fuzzy is likely mould or fungus. Check your ammonia, nitrite and nitrate levels to ensure your tank is cycled correctly.