I have a 24' Vogue AGP that we'll be installing in a week or two, and had a question about the cove. I've done a lot of reading about using a foam cove or building one up with sand, but my pool has one built in. It's in two sections, one built into the bottom track, and another piece that snaps into it. The instructions say this is enough, but is it really? Or do I still need to build it up?