I would be careful as Theo suggested with a pond that old. I think it can be placed in the deepest water and run a couple hrs.and add 1 hr. each day or night. If you place the diffuser inside the bucket on top of gravel so it will sink and be stable, tie a rope to the handle with a float on the rope for retrieval, it will work fine. I did put 2 18 inch pieces of 1/2 in. pvc thru bottom of bucket for stability as suggested by Cecil I believe.
PS definitely not a pro, but have learned from the pros.
