Thanx everyone for their input.... I do have a mechanical filter first, well the idea of a filter. Havent got to dig yet
I have two BD's feeding a mechanical filter leeding to bio then to another barrel that my pump is going to suck from.... should that last barrel be mech or bio? and another question was I want air through the two BD's and in any bio barrel, right? How much air?
background: roughly a 1600 - 1800 gal pond, homemade vortex & nexus filter, 2 air BD's that are 5 ft deep
thanx again for everyones help
another sleepless night as my mind wonders...... and stays with the pond