Pool care when it rains: This is what you should do before and after the storm!

On these unusual days in July we are experiencing unprecedented storms and flooding. You've probably noticed that too much rainwater not only harms your vegetable garden, but also your swimming pool. All pool owners who have theirMaintain pools yourself, one day face the problem: What do you have to do when it rains? Here are some tips on how to protect your pool against rain and restore good water quality afterwards.

Can a pool overflow due to rain?

First of all, you don't need to drain your pool before the storm, as this can cause major damage as the water protects the lining on the walls and floor. If you are still concerned that the pool may overflow due to rain, drain some water. There should always be 10 – 20 cm free to the edge.

If you have a swimming pool built into the garden floor, you usually don't have to worry about overflow, because the water drainage systems such as the skimmer or the overflow channel serve as overflow protection, like in a sink. The overflowing water is usually fed into a filter, cleaned there and returned to the pool via a pump.

When it comes to an above-ground pool or an Intex pool, overflow can only become a problem if the floor around the pool becomes unstable due to the overflowing water or if the water pressure becomes too great and the walls threaten to give way. However, an overflow rarely has such dire consequences. Even if the pool you set up overflows, only the excess water will flow out and not the entire contents of the pool. If the pool is too full due to the rain, you can drain some water into the drain or a plastic container using a hose.

Just for your information: 1 mm of precipitation corresponds to one liter per square meter. In June 2021, the average rainfall in Germany was 95 liters per square meter. So that's 95 mm or about 1 cm per square meter. A 30 square meter pool holds 37,500 liters of water.

Cover the pool when it rains or not?

It is not necessary to install a cover as heavy rain and wind still cause dust and dirt to get into the water and the cover can be severely damaged. In addition, after that you still have to somehow pump out the rainwater collected on the cover. So you can leave your pool open when it rains.

Some pool owners are also of the opinion that it is too much effort to close the pool light-tight for 1 or 3 days during a period of bad weather. This would make more sense if you are going on vacation for 2 or 3 weeks or are simply not at home.

To make cleaning after the rain easier, we recommend that you clean the leaves around the pool before the rain and add a little algaecide to the water to avoid algae formation.

If it is drizzling, it is possible to leave the filter running. However, heavy rain and thunderstorms can often lead to power outages. Experts recommend turning off the pool pump and filtration system and making sure they are protected from the rain. This also prevents the skimmer from becoming clogged with leaves and coarse dirt.

If flooding threatens to submerge the pool pump, it is best to turn off the pool's power using the main control panel. If you can safely remove the pump, store it indoors. If the pump motor becomes submerged, it will likely need to be replaced.

Rain typically does not cause damage to pool equipment, even if it lasts for days. If you're concerned, you can build some sort of weatherproofing for your filter pump. However, flooding is the real problem.

Pool is cloudy, milky or green after heavy rain?

It is not uncommon for pool owners to notice that the water has turned green and/or cloudy after a rainstorm. This is because rainwater contains dust, pollen, sand and other contaminants. If heavy rain falls on the pool during a thunderstorm, the pool water will be polluted by the rainwater itself. This pollution unbalances water parameters, especially pH, as rainwater has a pH of 5 to 6, while pool water requires a pH between 7 and 7.4. The quality of the pool water is then compromised, quickly leading to the proliferation of algae and microorganisms, as well as green water and a cloudy appearance. It becomes imperative to clear the green water so that it can be used for swimming again.

Clean pool after rain

After the storm passes, the first thing we need to do is lower the water level if it has risen excessively. How to bring the pool water to an appropriate level for proper cleaning. Set the filter valve to “Waste” mode and start the pump until theWater level at half of the skimmersstands. If you have a sand filter with a multi-way valve, you can simply switch it from vacuum to waste mode to drain some of the water from the pool without passing it through the filter.

Then remove all of themDeposits from the skimmer and the pump baskets. With a landing net you can remove surface dirt, such as insects, leaves and other elements floating on the surface. Also clean the pool deck to prevent dirt from getting back into the pool.

Turn that onPut the pump and filter system back inso that they can also filter out the small dirt particles. Use a brush or pool vacuum to clean the walls and bottom of the pool.Get dressed flocculantscan significantly speed up the cleaning process and may be required for sand filters.

Now you shouldMeasure water parametersto find out which ones are out of balance. Pay particular attention to the pH value of the pool water as well as the concentration of disinfectants and cleaning agents, i.e. chlorine, bromine or active oxygen. If a lot of rain has fallen into the pool, this will cause them to be diluted. As a result, their effectiveness is reduced.

After adjusting the pH to 7.2, you should take one in the eveningShock chlorinationcarry out and add some more algaecide. Leave that aloneThen run the filter system overnight. The next day you should analyze the pH and chlorine levels again.