worms i have a 20 gal tall tank w/ good filtration. ONE fish ,"JEWEL". Im having a problem w/ black worms growing in the tank. I took out all the decos and bleached. Stirred up the gravel real good and diatomed. Then refilled They are coming back. when you touch them they turn to an ash like substance. I barley feed so its not overfeeding. What are they and where are they coming from? Thank you for your time |