White Algae or White Mold on Filter
I have a roughly 10 year old 40 gallon tank with an electric yellow cichlid, a cory cat, a clown loach, a clown pleco, and a rainbow shark. For years I've been running a Penguin 350 power filter with an under-gravel as well. I recently realized after coming home from college that my under-gravel filter hadn't been working properly (for how long, who knows) and I decided to just get rid of the under-gravel altogether (I'll be getting an additional Penguin 200 on my next payday). I netted the fish into a bucket and did a huge water change and vacuum job to get all the gunk that was trapped under the plates out. After things settled more I turned the Penguin filter back on and let the water clear up before adding back my fish and decorations.
Even after the water cleared up the rest of the way I noticed little white floaters in the water. They're kind of feathery and certainly look to me like some kind of algae. I've now discovered that the source is a growth where the filter dumps the water back into the tank, as well as on the biowheels. I typically have some algae in that spot but I've never seen it on my biowheels. It is stringy which leads me to believe it's white algae, but I'm concerned nonetheless. Has anyone ever had anything like this happen in their tank? If so, were you able to determine whether it was algae or a fungus? If it's a fungus, is it dangerous for the fish and what advice do you have for remedying it? I've attached some pictures of the filter and biowheels in question as well as a close-up of some of the stuff floating in the water.
Any help would be immensely appreciated!