How to Drain an In-Ground Pool

Draining an in-ground swimming pool is dangerous and should not be done unless absolutely necessary, which means most often it is done because the pool is going to be resurfaced or repaired. In fact, for many pools, it is impossible to drain them completely for this very reason. Most experts recommend asking a pool service to come out and do it for you. This is because once the pool is drained, if there is water underneath it (from rain usually) the pool can actually heave up out of the ground. The rain water trapped under the shell creates something called a hydrostatic force, which is strong enough to lift the pool right up. Still, you can do it yourself if you are very careful.

Things You'll Need

• Submersible pump Discharge hose

Instructions

1. First, check for a hydrostatic valve, which is located in the main floor drain. Open it if there is one. If there is a plug there instead, remove it. Doing so might save your pool if it begins to do some hydrostatic floating.

2. Attach the hose to the sump pump and lower the pump into the water at the deepest end of the pool. Make sure the other end of the hose is draining into a safe place, such as your home's sewer drain pipe. This is usually a small black, capped pipe in your front yard.

3. Turn on the pump and begin to drain the pool. Check periodically to make sure the water is not overflowing out of the hose onto the street or your neighbor's yard. Try not to exceed 12 gallons per minute, as most sewer drainage pipes cannot handle more than that.

4. Stop pumping as soon as you can. It is best to leave as much water as possible in the pool to prevent both hydrostatic floating and cracking. Some pools, especially fiberglass, cannot handle the outside pressure well when they are not full of water.

5. Fill the pool again as soon as possible. If you let it sit empty too long, you will most likely ruin it and the surrounding area as well, especially if it is concrete or granite.

Tips & Warnings

• If you are planning on draining the pool water into a storm grate, check with your city regulations first.

Resources

• More about draining a pool or spa.