Does anyone know what these worm things are? I have a 60 gallon freshwater planted tank. The fish are a mix of rainbow fish and a few tetras with loaches and a couple algae eaters in there for housekeeping. My gravel is about 40% plant substrate and 60% standard gravel. I use a sump with built-in overflow, CO2, and 2 Current USA LED aquarium lights. Water parameters are all great and temperature is kept between 76F-78F. I have heard little guys like these can be a result of overfeeding but with the number of bottom feeders in the tank, I do not think I have an issue with excess food lingering around. Any help/advice would be great!