"Richard Holub" wrote in message
...
Hey,

Does anyone know if it is normar to find a skim layer of "black sludge" at
bottom of tank and directly on top of all filter media at end of season
with a Skippy Filter. I found approximately a 1/4 inch of sludge which
did not totaly "stink" but did have a slight hint of decomposition by
anaerobic bacteria. This was the first season I experimented with the
Skippy Filter on my "NEW" 700 gal. pond. Next year the pond will empty
into a larger 4000 gal. pond with a vortex filter. The small pond will
actually become a vegy filter.

I have the same thing on mine but don't see it as a problem. Arrow plant,
water celery and hyacinth in the top.
JD
http://www2.itexas.net/jdstone