Above ground pools can be more difficult to clear because of smaller filtration systems. For best results, use a flocculating agent. A quart of "Drop-out" or "drop-down" will work by settling everything to the bottom of the pool, including all of the "green" and then can be vacuumed to waste (not back to the pool). You'll have a few inches of water loss using this method, but it's usually very effective. To use a flocculating agent, elevate the chlorine to 10ppm. Brush the pool. Add a quart of Drop-Down. Run the pump for 2 hours, then shut off the pump for 24 hours. Everything should sink to the bottom. Vacuum to waste then re-balance water chemistry.