Went to feed my little ones last night and found this in the qt bowl my one guy is living in. It's a HUGE tuft of white cottony stuff. I have no idea where it came from. The bowl has been covered by a piece of black plastic mesh so I'm sure it hasn't fallen in from somewhere.
I had lots of "white cottony stuff" in my tank when I first put my heater in; it was around the suction cups. I don't know where it came from but I'm pretty sure its harmless as it was also in a guppy fry tank I had and it didn't effect them. Its easy to get rid of; just scrathch/brush it off; although it will grow back quite quickly. Eventually, it will just die off.
was it kind of slimy when you touched it? i just did water changed and on both my heaters in my bettas tanks i had this and it was slimy so i took them out and scrubbed them with an algae pad in the bucket of water i was taking out from the tank. i get it ocassionally. i guess its slow to come back, but its kinda yucky lol