Question from Luther:
I can see little white worms swimming in the tank. Do i need to treat the RES and the tank?
Sounds like you may have Planaria in your tank. Planaria are flatworms, related to flukes and tapeworms. They are quite small and hairlike. Take a good look at them and you may see a hammerhead shape on one end with eyes.
Bottom line, they are not harmful to turtles.
However… they are an indicator that the tank has a problem. Either you are feeding your turtle (You do have a turtle, right? Making an assumption here since you didn’t mention, but you are asking this question on a turtle website) too much, or you are not cleaning your tank enough.
I say this because Planaria require a food source, which means there must be excess food wastes in the tank to support them.
If you want to get rid of them, you should: