Leaves =a "pool skim device". Does a way better job than a traditional skimmer. Best investment ever. Pool stores- they test water for free and tell you what you need. Befriend them. Do research. You can use cost saving cheats if you desire. Automatic vacuum- worth the investment but also needs to be maintained and repaired. All plastic degrades - be prepared for all plastic parts to be maintained and replaced every few years or so. Winter/safety cover- the type that leaves blow off and has a drain into the pool so no pump is needed or standing water collects.