How to properly drain your inground pool - Sutro, Inc

How to properly drain your inground pool

Learning how to drain a pool can seem daunting. We love to have our swimming pool full of crystal clear water, available to enjoy 24/7. However, as a pool owner you must face the fact that draining your pool is necessary every certain amount of time

Fortunately, the process to drain your pool should be done every few years. But how is it done? It’s not as easy as pulling a plug and not doing it properly could cause serious damage. At Sutro, your trusted Smart Water Monitor, we want to make sure you know how to properly drain an inground pool and when to do it.

Reasons why you need to drain your pool

Emptying a pool is a process that is required to be done only every few years to perform specific tasks or in very special situations. Let’s take a look at them.

To restore the water

You can be on top of things and have your pool chemicals constantly tested, however sometimes chemical balance can be out of control and that means you need to start from scratch. 

Say for example you’ve been adding the proper sanitizers, but after months or even years, the residue of all the chemicals you’ve been adding for so long, combined with the regular pool contaminants like debris, can mess your water’s balance. This is called TDS (total dissolved solids) and will interfere with your ability to keep the water properly filtered out. 

You can supervise your TDS levels with a Smart Water Monitor like Sutro.

For pool maintenance tasks

Any pool maintenance related task, like painting, fixing cracks or cleaning calcium deposits, will have to be done sooner or later. Even though most of the basic routine procedures to keep your pool fixed can be done with water in it, sometimes you need to drain a pool to perform these tasks.

When you want to find out how much water your pool has, you can use your pool volume calculator

To prepare for a hurricane

You must prepare your pool in case of a hurricane or tropical storm, as it might cause it to overflow. It’s very important to know that in a case like this, you must NOT drain your pool completely. 

An empty pool during a hurricane is vulnerable to “floating”, in other words, popping out of the ground caused by excessive groundwater pressure, that could create serious damage to your pool. 

In such a case, you want to drain some water to prevent it from overflowing, but you should NOT drain your pool past the bottom of the skimmer.

When should you NOT drain your pool?

If you have experienced heavy rains the best you can do is wait. Accumulated rain water can cause pressure on the sides, increasing the risk of floating. Allow a few weeks for the ground to dry out. 

Prepare a game plan before draining 

Before you start considering draining your pool, you need to prepare a game plan. Keep in consideration that you’re about to dispose of thousands of gallons of water and it’s got to go somewhere. You definitely don’t want all those chemicals ending up in your yard.

Consult your local authorities

The best advice in this case is contacting your local authorities to consult what is allowed and what is not. In some areas, it’s allowed to direct it to your own sewer and even into the street, but others have certain restrictions regarding pool water disposal. Always check first to avoid possible fines. 

Some areas also require pool water to be chlorine neutral before it’s drained. It’s always advised to:

  • Consult your local authorities about the chemical levels your water must have before draining. 
  • Stop treating your water for chemicals before you plan to drain your pool.
  • Finally, test your water to make sure your water meets the levels required.

Get prepared for your water bill

Keep in mind that you’re about to replace a gigantic amount of water. A standard inground pool sized 12×24 feet, with an average 3.5 ft depth can hold approximately 7,600 gallons of water. A pool of the same dimensions with a 5 ft average depth can hold 10,800 gallons, so you get the idea. Prepare the budget for next month’s water bill.

Choose your draining pool day wisely

Draining a pool takes time and depending on its size, it may take approximately between 8 to 14 hours to drain. You may want to choose a day you can direct all your attention to the process because it is not recommended to leave it unattended.

At the same time, ut’s not wise to keep your pool empty for too long. Keep in mind the process of filling your pool again will take more or less the same time, so pick a time when you’ll know you’ll be 100% available in case you experience any issues. 

Take weather into consideration

A sunny, not too hot day is the best possible weather you can have to drain your pool. An empty pool exposed too long to extreme heat is vulnerable to damage. Preferably, pick a day where the temperatures won’t rise beyond 85ºF (29ºC). 

How to drain a pool – Inground

Now that you’re set to start, let’s see the steps you need to take to drain your inground pool.

1. Get a  submersible pump

Make sure to turn off the pool pump and pool lights beforehand. Attach your garden hose to the submersible pump and place it in the deep end of the pool. Make sure the power chord is long enough to reach the power outlet without stretching too much. 

You also want to make sure the hose is long enough to get to the draining spot you are legally allowed to dispose of the water. 

Pro tip: Avoid using the pool pump to drain the pool. Once the water level falls below the skimmer it will start sucking out air instead of water, causing plenty of damage. Be sure to buy or rent a submersible pump.

2. Start draining!

Turn on the submersible pump and make sure all the hoses are properly connected. Also, keep an eye on the draining hose, making sure it is directed to the disposal location.

3. Turn off the submersible pump

It will come to a point where the level of the water is so low that the pump won’t be able to drain anymore water. Once you reach that point, turn the submersible pump off.

4. Open the hydrostatic relief valves

Also known as hydro-valve, it prevents groundwater pressure to cause your pool to “float”. Unscrew the plugs and open the hydrostatic pressure relief valves so any remaining groundwater can enter the pool. Use the pump to remove the groundwater.

5. Replace the hydrostatic plugs

Is very likely that opening the hydrostatic plugs may cause them to be damaged, so it’s best to be prepared and have new valves to replace them in such a case. Replace them before refilling your pool again.

Now you’re ready to perform work on your pool. Whatever task you do, make sure you don’t take too long, preferably no longer than one week. Once you’re done, you’ll be set to start filling your pool. 

When you’re ready for National Pool Opening Day again, it will be time to balance your newly renovated water for more years of pool enjoyment.

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