I don't think so. What is the water clarity of any other ponds in the area? If light can get to the bottom of the pond, then weeds could grow. So, I think a little more depth is better than not enough depth. If the bloom is good, then anything deeper than 48" shouldn't grow weeds.

As for compaction rates, I don't know. A valve on the siphon will give you more leeway in draining the pond down if needed.

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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).