Lots of different ideas - they all equate to tent. Fill a coffee can with concrete and a pole in the middle - voila! you have a tent pole that doesn't have to poke through the liner.
Netting over a pond does reduce visibility - but mostly for cameras. My camera wants to focus on the net, instead of the pond below. The human eye is more discerning. You will shortly not notice it.
My personal belief is that jumping is a character trait of some fish. Jumpers are going to jump when startled. When you are looking to buy a fish, look for the "divers".
Some fish will jump when startled. Some fish will dive to the bottom. The divers will consistently dive. The jumpers will consistently jump. The jumpers don't live long.