On May 27, 8:19*pm, gaijin wrote:
My tank is several years old and I haven't added anything new in well
over a year. *Today when I got home there was a large mass of what
looked like tangled string attached to a rock. *The mass is about the
size of my fist and there was no sign of it yesterday. *I grabbed some
of it and it breaks apart fairly easily so it is rather soft.

Anyone have any ideas as to what it could be?

No one in this group really gives a flying **** on what is in your
dumbassed fish tank dude. Its probably a big ****ing hair ball from
your wife or momma that they coughed up. Deal with it.