If you have an accumulation of debrie collecting in one area, That area is not getting enough current, This could become a problem in the long run. A PH
should be directed to that area of the tank. What size PH
and how many are you using, What type of filtration are you using? What size tank do you have.
xxmoorishmanxx I had a bunch of Bumble Bee snails in my tank. I called them my Grim Reapers, When they showed up in one place in numbers I knew something was wrong. They do a great job cleaning up the tank.