Pond Cages

Dear All

My pond is rougly 2m x 3m. With some tall standing plants in the pond

We have a big problem with herons and other predators

My old hand built, net covered, wooden cage frame, 1m high, is nearing the
end of its life.

What do other people use to protect their fish?

I was looking at aluminium frames but they look expensive

I live in the uk. Any suggestions and advice will be much appreciated

Mark