IMO It doesn't matter what type of CC it is they all get big and they will eat anything. Specially flatheads! There like fresh water sharks. If they are hungry they'll eat it!
Being here in Arkansas a LOT of folks here like CC and they ask me all the time do I have any in my pond? When I say nope there all like why not?? Why not so I don't have to go through what your going through now.
What you put in your pond is SOOOOOOOOOO critical 1 wrong move and it can mess up everything you tring to do for a long, long time!!
RC
