Thanks everyone. I swear I am going crazy over this. I went out again this morning and was even late for work because I did not want to leave the pond until I had found a turtle! No luck. What is so strange is that we see the huge ones in the lake and the mud pond all the time. They stick their heads up out of the water and walk across the back yard now and then. They are HUGE! Nothing of that size could be in my small pond without my being able to see it.
I cleaned the filters and used the vac over the weekend. The water is very clear and the bottom is almost spotless (for a pond!)
I stood on the side with the longhandled fish net and lifted all the pads one section at a time. I could see in every lily pot and see the entire bottom. There was just nothing to see. If somehow a very young small snapper got in there and could hide between the pots on the bottom, then it is possible I missed him. I know for a fact none of the big lake ones are in there! I walked around the entire outside of the pond and looked and poked the plants and vines in case he was out sunning. Again, nothing. My DH said it is a turtle from the lake that has found the watergarden and takes an evening stroll up to the all you can chomp lily bar.
I know I have every chomped pad out of the pond as of this morning. If there are none detatched when I get home, I will sit out on the deck this evening and wait. His A$$ is mine if he shows up! He will find himself in another county before midnight!