How to Drain a Pool
Your swimming pool is a source of much fun and pleasure. All good things come with a price, and you undoubtedly know that pool maintenance is one such cost. One part of maintaining your pool is the infrequent need to drain it—because of repairs, water quality issues, or long-term pool closure.
Draining your in-ground or above-ground swimming pool is not particularly difficult. But it is more involved and requires more planning than simply popping open a drain and letting the water run out.
Reasons to Drain Your Pool
A well-maintained swimming pool rarely needs to be drained of its water. Whether you initially filled the pool with treated municipal water or from a water truck, that water came at a high cost. So, a better option than draining your pool is to zealously protect your pool's water quality and the physical condition of the swimming pool itself. Still, there are a few reasons why you may need to drain the pool:
- Pool Water Quality: When total dissolved solids (TDS) reach 2,000 ppm or higher, it can be difficult to correct the water quality. Excessively high cyanuric acid (CyA) levels, too, may warrant pool water drainage. With either TDS or CyA, you reach a tipping point where the addition of more chemicals cannot correct the water quality.
- Pool Maintenance: When the inner surface of the pool needs to be resurfaced, cracks repaired, or painted, you have no other option than to remove the water from the pool and let it completely dry before the repairs.
- Long-Term Pool Closure: Swimming pools should remain full of water through all seasons. But sometimes, pool dormancy extends so long that it makes more sense to drain the pool than to keep it maintained.
Where to Drain the Pool Water
- Sanitary Sewer: If your community allows you to drain the pool water directly into the sanitary sewer, this is often the most efficient way to route the drainage water. You will also need access to the sewer, usually via a storm drain.
- Irrigation: If the water quality is conducive to plant life, permits often allow you to discharge pool water to your own property. Discharge hoses range from 50 feet to 300 feet long, though discharge will also be limited by pump capacity.
Codes and Permits
Many communities require you to obtain a pool drain permit. Upon applying for the permit, you may be required to declare water quality test results for pH and chlorine levels, as well as describe other contaminants in the water such as dirt, debris, and algae.
When to Drain Your Pool
Do not drain your in-ground swimming pool after a period of heavy rain. Waterlogged soil may force an empty in-ground pool basin to rise. Instead, wait until the ground is dry, with all of the water percolated away, before draining your pool.
Above ground pools can be drained at any time since hydronic pressure is not an issue. Above ground pools may not require a pump to drain. There is probably a drain valve somewhere around the bottom perimeter that a discharge hose can be attached to.
What You'll Need
Equipment / Tools
- Submersible pump (rental)
- Pump discharge hose
- Pool skimmer
- 1 50-foot Nylon rope
- Shop vacuum
- Trash bag(s)
Obtain a Submersible Pump
Submersible pumps can be rented at many home centers and rental yards. Look for a 2-inch submersible pump with a capacity of at least 60 gallons per minute (gpm). Also, rent a discharge hose that is long enough to reach your final discharge point.
Attach the Discharge Hose
Screw the discharge hose onto the submersible pump. Unfurl the discharge hose to its full length. Because discharge hoses are flat, they must remain flat on the ground to properly expel the water. Untwist the hose to flatten it.
Clean the Pool Water
Two-inch submersible pumps generally can move debris up to 1/2 inch in diameter. With the pool skimmer, remove as much debris as possible above that limit, and deposit it into a trash bag. Turn off and unplug the pool filter.
Submerge the Pump
With the pump unplugged, submerge it into the swimming pool at the pool's deepest point. Do not drop the pump to the bottom of the pool. Gently let the pump down with a rope looped through the pump's handle. Remove the rope so it does not get pulled into the pump.
Plug in the Pump
Submersible pumps must be plugged only into ground-fault interrupter (GFI) outlets.
Monitor the Pool Draining Operation
Keep an occasional watch on the pumping operation. Make sure that water is always being expelled from the end of the discharge hose.
Running a dry pump may irreparably ruin the pump. When running, the pump must always be moving water.
Clean Up the Remaining Water
When the water is too low for the submersible pump, turn off and unplug the pump, and then remove it from the pool. Use the shop vacuum (without a bag or filter) to clean up the rest of the water at the bottom of the pool.