How to vacuum a pool
Vacuuming removes dirt, leaves and dead algae that settle on the floor, before they use up chlorine or stain the surface. Manual vacuuming through the skimmer takes a few minutes once you know the steps. The main decision is whether to send the dirt through the filter or straight out to waste.
What you need
- A telescopic pole.
- A vacuum head suited to your surface: brushes for vinyl, wheels or brushes for plaster and concrete.
- A vacuum hose long enough to reach the far end of the pool from the skimmer.
- A skimmer vacuum plate, or an adapter that fits the skimmer's suction port.
How to vacuum through the skimmer
- Brush first. Brush the walls and steps toward the floor, then wait for the dirt to settle.
- Check the water level. It should be at least halfway up the skimmer opening, or the pump can draw in air.
- Clean the skimmer and pump baskets, and note the filter pressure.
- Assemble the head and hose, and lower the head to the floor.
- Fill the hose with water. Hold the free end against a return jet, or feed the hose down into the pool, until no more bubbles come out of the head. Air in the hose can make the pump lose prime.
- Connect the hose to the skimmer, keeping the end under water: through the vacuum plate, or directly into the suction port.
- Vacuum slowly, in overlapping strokes from the shallow end to the deep end. Moving too fast stirs the dirt up instead of picking it up.
- Watch the filter pressure. If it rises sharply, stop and clean the filter or empty the baskets.
- Finish, disconnect the hose, clean the baskets, and backwash or clean the filter if the pressure is up.
Filter or waste?
Sand and DE filters usually have a multiport valve with a Waste setting, which sends the water out of the pool without passing through the filter.
- Vacuum on Filter for normal dirt and debris. The filter catches it, and you don't lose water.
- Vacuum to Waste for heavy loads: dead algae after shocking, fine debris after a storm, or particles that a flocculant has dropped to the floor. Fine material like this passes through or clogs the filter. It's also useful if the pool is overfull.
Always turn the pump off before changing the multiport valve position, then turn it back on.
Cartridge filters usually have no Waste setting. For heavy loads, vacuum through the filter and clean the cartridge afterwards, sometimes more than once. Some systems have a separate drain valve for this.
How much water vacuuming to waste uses
Water leaves at the pump's flow rate. At 50 gallons a minute, 10 minutes on Waste removes about 500 gallons. In a 15,000-gallon pool with an average depth of 60 inches, that's about 3.3% of the water, and the level drops about 2 inches (3.3% of 60 inches). Keep a hose running into the pool while you vacuum to waste, and stop if the water gets close to the bottom of the skimmer opening.
The water you replace dilutes chlorine, stabilizer and other chemicals a little. Retest after a long session.
Automatic cleaners
- Robotic cleaners run on their own power, have their own filter bag or basket, and don't load the pool filter. Clean their filter after each run.
- Suction cleaners connect to the skimmer or a dedicated suction port and send debris to the pool filter, so check the pump basket and filter pressure more often.
- Pressure cleaners run off a return line, often with a booster pump, and collect debris in their own bag.
Even with an automatic cleaner, brush the walls and steps regularly, and vacuum by hand when there's dead algae or very fine debris.
Frequently asked questions
How often should I vacuum my pool?
Often enough that debris doesn't sit on the floor for long. For many pools that's weekly, and more often after storms, heavy use or in pools under trees.
Why does my vacuum lose suction?
Usually air in the hose, a low water level, full skimmer or pump baskets, or a dirty filter. Re-prime the hose and check each of those.
Should I vacuum before or after shocking?
Brush and vacuum loose debris before shocking, so chlorine isn't wasted on it. After shocking for algae, vacuum the dead algae, often to waste. See how to shock a pool.