I'm in the process of placing cover in my pond and we ran into a problem today. I was going to use T-posts to anchor things in the pond like logs, brushpiles, etc. but there is nothing but hard rock a few inches under the clay. How would you anchor these things down? The best I can come up with is 5 gallon buckets filles with quickrete. Any suggestions?

I started with nothing, and still have most of it.