Worm like thing on wall

Question
My son has a small 5 gallon tank.  All of a sudden we have noticed these little worm like things on the wall.  They remind me of like a parasite you see in science.  I cleaned the tank and changed the filter, but they have returned.  Is there something I need to add?

Answer
Hi Vickie,
There are many critters that can show up in our aquariums and although it might be a bit alarming-- Fortunately most all are harmless scavengers but while the worms themselves are not dangerous to the fish, their presence usually means the aquarium needs a bit more frequent water changes and gravel vacuuming to remove accumulate debris on the bottom which is what the worms are thriving on.

They are most likely Planaria and the best way to get rid of them is to start doing daily 30% water changes and making sure you aren't overfeeding your fish. With time their food supply will be depleted and they will disappear. Preventing their re-occurrence is a simple matter of doing 1 - 2 extra water changes than normal as part of your normal maintenance schedule. They shouldn't return.

Best of luck and hope this helps!
Karen~