If your visibility (or lack of) is due to suspended clay, then you need to look into an alum/hydrated lime mixture. That's my understanding anyway. If your visibility is due to algae/phytoplankton bloom, that's not necessarily a bad thing unless your shooting for a gin clear pond. If that's the case you can look into barley straw or barley extract to clear up your water.

.10 surface acre pond, 10.5 foot deep. SW LA. The epitome of a mutt pond. BG, LMB, GSF, RES, BH, Warmouth, Longear Sunfish, Gambusia,Mud Minnows, Crappie, and now shiners!!...I subscribe!!