Karmex aka Diuron is dangerous in ponds and can easily damage the pond ecosystem especially the plankton forming the basis of the entire pond's food chain. Thus the entire fish community and pond ecology suffers and at times can be eliminated or significantly damaged due to collapse of the food chain and/or loss of dissolved oxygen due to too many plants dying. Diurion apparently does accumulate in fish flesh.
See this good information exchange from a previous topic:
http://forums.pondboss.com/ubbthreads.php?ubb=showflat&Number=33898

Also see this forum discussion about Karmex:
http://forums.pondboss.com/ubbthreads.php?ubb=showflat&Number=502143#Post502143

Last edited by Bill Cody; 02/18/19 11:15 AM.

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