Pools can quickly become covered in algae if the pool is left unattended even for a few days. The best way to prevent algae growth is keeping the pool well-chlorinated. Removing established algae can be harder task, but it's possible to use a pool vacuum to clear away the algae that's fouling your pool. Start by making sure all your tools are in working order.
Assemble the pool vacuum if you haven't used it before. Attach the vacuum head to the hose, then connect the hose to the vacuum pump
Sink the vacuum into the pool slowly before turning on the pump. This helps retain the proper suction that is necessary for the vacuum to work. Lean the vacuum against the pool wall.
Put on an old swimsuit and a pair of gloves. Skim the top of the pool with a pool skimmer; sometimes algae is present on the top of the pool, which prevents you from seeing the pool bottom. Clear the algae off the pool surface so you can see into the water. Discard the algae and other contaminants far away from the pool, or in a trash can.
Sweep the pool bottom and the sides of the pool walls with a long-handled brush to loosen any algae and contaminants that are firmly attached to the pool floor or stuck to the walls. Allow the water to settle for several minutes to a half-hour.
Turn on the pool vacuum. Vacuum up the algae and debris that have settled on the bottom of the pool. Work slowly and use long, sweeping motions to prevent the algae from becoming stirred up. If algae remains, brush the walls and floor again and repeat the vacuuming process.