One difficulty with above ground pools is that some varieties of grass and weeds have very deep and stubborn root systems that survive grass clearing and leveling work. These will eventually grow up through the liner of your pool. In order to help prevent this, you should consider placing an additional barrier beneath the pool. The ground cloth included in the kit helps and should be installed, but it isn’t very thick or durable so the protection that it offers is limited. One excellent idea is roofing tar paper because of how thick and sturdy it is. Another, more conventional, idea is commercial grade landscaping fabric often used in flowerbeds. It’s not as thick or durable as tar paper, but it is less expensive and easier to install.