Derek, just try to have your winter diffuser holes close enough to shore that if anything goes swimming that it/they can get to shallow enough water to get back out. I almost lost 2 Springer Spaniels that way. I now have the diffuser closer to shore.

I use my personal pond for testing. That way if a test fails I don't have customers that aren't happy with me. wink grin

www.hoosierpondpros.com

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3/4 to 1 1/4 ac pond LMB, SMB, PS, BG, RES, CC, YP, Bardello BG, (RBT & Blue Tilapia - seasonal).