i need help now

[draco]

there were alot of briste worms all over just hanging out of the rocks i have never actually seen one in my tank until now. i havnt lost any of my pets(animals i have purchased) recently, but i dont really know what might have been living in there. so you think that i sould do a big water change then add my fish back in. and run only carbon in my filter. ohhh i have been using something in my filter called greenX, do you think that this may have done something to my tank? i dont know what happens when it has expired or it is does.