okiefish16 Welcome
Sheetrock has a paper facing along with fibers (fiberglass?) and chemicals mixed in to reduce cracking and improve fire ratings. I would avoid sheet rock in any significant quantity for those reasons.
The "active" ingredient in sheetrock is gypsum. Gypsum can be a help in reducing turbidity in ponds that have a lot of clay particles which cloud or muddy the water. Gypsum works by "clumping" particles together so they sink.
Gypsum is available as agricultural pelletized gypsum from home and garden centers.
I have used bagged agricultural gypsum with some sucess.
Many gardening references say gypsum is helpful in "loosening" clay soils assisting in better drainage and improving soil stucture.
A search on Google for [soil gypsum] or [gypsum pond] will yield much more information.
If you decide you NEED gypsum, I suggest you use the real thing, not sheetrock with fibers, fire retardant chemicals, etc. Bagged gypsum from the home/garden center is not very expensive.
dave asked an important question [why do you think you need it??].
See
http://www.pondboss.com/ubb/ultimatebb.php?ubb=get_topic;f=16;t=000066 for a previous thread on gypsum.
Another article from Kentucky is
http://aquanic.org/publicat/state/ky/liming_wp.htm which states
[Adding agricultural gypsum to ponds to precipitate available phosphates which can reduce dense algae blooms, increase water hardness and may reduce turbidity. ]
I hope this helps. Good luck!
Frank
