AG pool cove

[lewdczy]

Has anyone used the Gladdon cove on there pool? I bought it and installed and when I started filling my pool my walls started to cave in. I notice the liner wasn't touching the cove. I looked back on my direction and they show an 8"x8" cove and the Gladdon cove measures 3"x4". I removed the liner built the cove up with sand and reinstalled so far it seems to be working.