In order to keep a pool looking clean and beautiful, both in-ground and above-ground pools have a filtration system which takes out particles and solids that can make pools appear cloudy or even green. The most confusing piece of the whole filter set-up is the backwash valve, which has a range of settings that can keep the pool running beautifully.
For the bulk of the time, the system will run in "Filter" mode. This pumps water through the filter chamber itself, which forces it through smaller and smaller spaces and pulls out particles that are floating in it, allowing only clean water out. Recommended minimum pump time in "Filter" mode is between 6 and 8 hours for both above- and in-ground pools, although if you plan to have a pool party with many extra users, you may want to run it for a full day before and about 48 hours afterward.
Many pool set-ups include a timer mechanism that will turn the pool pump on and off at certain hours of the day. The timer itself usually includes a disc with 24 hour increments, and a set of On and Off clips, allowing you to dial in the times you would like the filter to run and when you want it off. While the pool system includes many countermeasures to prevent swimmers from being harmed by the pump system, it is a machine that carries a small risk of injury--as a result, many pool owners have the pump off when the pool is in use. That said, it is a matter of preference: if kids will be using the pool, it may be safer to leave it off; if primarily adults are swimming, they will likely be fine either way.
Keep an eye on the PSI (pounds of pressure per square inch) gauge, as the pool will need backwashing periodically. Look at the user's manual for your pump system to find out what the PSI levels should be for normal use and when a backwash cycle is needed, or consult your pool professional. Generally, the level is about 10-15 PSI higher for backwashing than when functioning regularly.
Backwashing flushes out debris from your filter. When backwash mode is required, switch the backwash valve to the mode and run the pump until the water in the small glass viewer is clear. The viewer, usually a small glass jar or bubble, will show you the color of the waste water passing out via backwash. This process should take less than five minutes, but the clarity of the waste water is your best guide.
After backwashing, be sure to turn the backwash valve to "Rinse" for about 30 seconds before returning the pump to regular Filter mode.
During regular upkeep, vacuuming the pool will keep out the solids which unintentionally fall into the pool during use. To vacuum, switch the backwash valve to "Waste" mode and attach the vacuum to the pool's skimmer. Anything being vacuumed bypasses the filter--keeping it cleaner for regular use--and is ejected with the waste water. You should run the "Waste" mode like this until the vacuuming is done, which shouldn't take much more than 20 minutes at most, but do keep an eye on the water level while doing this--it should be about halfway up the skimmer. Water splashes out of the pool when people play in it, and some evaporates during the summer, so you may need to top up after vacuuming
On very rare occasions, most often when vacuuming heavy solids, the pipes may become clogged by something in the pool. In these situations, the troubleshooting mode is backwash filter to "Recirculate" option. This forces the water through the pipes, which can clear blockages and restore regular pressure. Run the recirculate mode for a few minutes at the most, until the blockage is clear; if it can't clear the blockage, call a pool maintenance expert.