I concur with Donno. Using cloth under the rock might be more expensive up front, but it's a LOT cheaper in the long run. Every 2-3 years you'll have to be adding rock without it as the rock will get pounded down into the ground. Round rock slides, and will push out from under the tires even faster.

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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).