pvc clamps

[Reef-Geek]

Hi guys, I am setting up a new tank and wonder what's the best way to clamp PVCs to the stand?

There is at least 4 inch spaces between the PVC pipes, I was thinking of using this kind of clamps but I don't know how to fill the spaces.


Also how to stabilize the PVCs that are over the sump, I saw people use some kind of chain but I don't know if that's stainless, any options are appreciated. thanks.