GOT SAND?
Couldn't resist. So what, now we're being graded on attendance?
Is it Pass Fail or ABCDF?
Tanks looks good! I like them when they are all shiny and new like that.
Bring on the grunge!
And Lynn, not sure about all the different bacteria's, but alot of them will grown on tank walls, plumbing. Just about any surface and to a lesser extent the water column. The only one I would think that would be there in any real numbers would be the ones that convert nitrate to nitrogren gas as they need an anerobic (low oxygen) environment.