Nan - I would screen the media to eliminate the small bits that are
clogging the screen. New media needs to be broken in by running for 8
hours without jewelry, then rinsed and screened to eliminate the
flashing that often exists on newly formed media.
I use the smallest screen on the parts separator as a screen. If you
don't have the parts separator, use some loose wire mesh. This is
backwards from how the parts screen is designed to be used. The
normal use is to dump the tumbler contents on the screen, the media
falls thru and the jewelry stays on top.
I would work outside, with a hose or a big tub. Put part of your
media in the fine screen and then wash vigorously and the fine stuff
will fall out of the more coarse media. Repeat until you have only
the normal sized media left.
In any case, don't put the small bits down your drain. They will
clog it for sure. If you must work inside, let the small bits settle,
drain off the clear water, let the bits dry out and discard with your
trash. I do this outside and my roses love the extra bits of texture
since our soil is not very porous.