You will have to use a Go-Flo bottle.  It is a tube, open at both ends that
closes when you send a messenger down to trip the tops and bottoms to
close. Then you haul the sample up.  It is a very common device used by
limnologists, people who study lakes.  I believe they come in different
sizes.  The one I used was made of plastic which could be acid washed. We
were measuring trace metals, so the bottle had to be trace metal clean.




Cecily C.Y.Chang
345 Middlefield Road
USGS Mailstop 434
Menlo Park, CA 94025
650-329 4471  Fax 5590
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