Bunchgrass Farm, I'm presently using an empty 1 gallon plastic jug with short rope to suspend my 2" irrigation pump pickup line. I'm expecting to switch said jug out for a Canada goose decoy.

Some folks around here use two mallard decoys tied together side by side to suspend theirs. The two ducks crowding each other look less than natural to me. One duck decoy may not have enough floatation to do the job for you.

We have reports of two reservoirs here in sw Colorado with blue green blooms. Advisories are out for those two BOWs. There have been no reported deaths so far.