FWIW, my memory might be wrong, but long term fix with ESS-13 had the same results as with bentonite. I think one guy in New England/New York area tried it. IIRC after a year the problem came back.


www.hoosierpondpros.com

[Linked Image from lh6.ggpht.com]
http://www.pondboss.com/subscribe.asp?c=4
3/4 to 1 1/4 ac pond LMB, SMB, PS, BG, RES, CC, YP, Bardello BG, (RBT & Blue Tilapia - seasonal).