I've done a grow in a Ga. swamp with a block of styrofoam,painted camo.2 blocks, each was 8 inches thick with a hole cut for each 5 gallon bucket. Layed a peice of screen to keep the soil in the buckets. They were placed where the pond spilled into the swamp. The pond was built by beavers. It was fairly successful! It can be done. The larger your base the better chance you'll have to finishing them.