We have used lots of tires. Small tires, car tires, tractor tires you name it. We cut a hole in each side so that they will easily sink. We normally place them in the shallower water. We have watched bream, bass, and especially catfish all use them for spawning. You cannot see the tires under the water. We do not stack them for this reason. There are tires in our ponds that have been in there for 15-20 years. No negative affects that we know of.
