Heavy rains will dilute your pool alkalinity level, causing it to fall by 5-10 ppm a day. Low Alkalinity and low pH levels in pools can create a corrosive water environment. Corrosive pool water can result in the damage of underwater metal surfaces, such as pool lights, ladders and rails.
When rainwater and 'run off' enter the pool, they can change your water's pH, calcium hardness, total dissolved solids (TDS), alkalinity, and other chemical levels as well as bring contaminants such as dirt and debris into the pool.
When preparing your pool for a storm, leave it uncovered. Installing any kind of cover across the pool will not do much to protect against dust and contaminants because storms often bring strong winds and heavy rain that can cause the cover to lift off your pool.
The Department of Environmental Health recommends avoiding activities such as swimming, surfing, and diving for 72 hours after it rains. Research has shown that the risk of infection is the highest during and the day after rain, and declines to around normal levels after three days.
The extra filtering will help clean out the impurities rain has introduced into your pool's water. Pool pumps are made to withstand rain and it is beneficial to run your pump during or after rain.
One heavy rain is all it takes to throw off your pool's chemistry by unbalancing the pool water's pH and making it slightly more acidic. This additional acidity and nitrogen provide a breeding ground for algae that will turn your pool green.
But large quantities of precipitation combined with an overflowing pool and poor drainage can cause problems such as flooding, structural damage to the surrounding buildings as well as out of balance swimming pool water chemistry. No fun.
If the pool overflows, now only will the pool chemicals be diluted, but they may contaminate the pool deck and surrounding landscape. Removing excess water quickly is important to prevent this.
Having an excessive amount of water added to your pool in a relatively short timeframe can lead to several problems, among them, malfunctioning of your pool equipment, the accumulation of algae and deck damage.
Why Your Pool Turns Green and Cloudy
This can alter your pH levels and dilute the chlorine or other sanitizers, allowing algae or other contaminants to gain a foothold. Once the algae spores have the proper conditions to grow, they multiply very quickly, which is why your clear pool can turn green overnight.
Rainfall dilutes pool chemistry levels and lowers the readings for pH, alkalinity, hardness, stabilizer, and chlorine. Rainfall does not contain chlorine.
"Heavy rain dilutes pool chemicals, especially salt and chlorine, which causes the pool to turn green. This means the water is not sanitised or healthy, so it's vital to address this.
Shocking your pool isn't necessary, although, it's not a bad idea either. If you get an extremely heavy rain fall, you could shock your pool for good measure. This will help fight off any contaminants that the rain may have brought to your pool.
Should the green be due to pollen, there may be little to do in the way of minimizing the discoloration short of erecting a building around the pool. Fortunately, assuming there are no allergies to the pollen, it is safe to swim in a pool with that as the cause for green water.
ADD POOL CLARIFIER
The change in your pool water colour means that you have successfully eliminated the algae and can now clean it out of your pool. If your water is still green, wait another 24 hours and redo the steps from Days 1 and 2.
With a rain storm, any number of contaminants can be washing into your pool – acid rain, pollen, insects, tree droppings, dust, sand and even phosphates. Any one or combination of these things in rain can make your pool cloudy.
Lower the water level in your pool to keep proper skimming action, and to avoid contamination from planters and deck area flooding. For most pools with a sand or DE filter, the simplest way to lower the water level is to place the multiport valve onto the waste position and roll out the backwash hose.
Algae overgrowth is the most common cause of a green pool.
Algae are normally kept in balance by water circulation, natural die-off in cool weather, and appropriate chemical balance. If the water circulation or chemicals are off, algae can bloom and cause a pool to be cloudy and green.
Every pool must turn over at least once a day, so most pool pumps should run approximately 8 hours a day. But here's the thing: you don't have to run your pool pump consecutively. You can choose to run it for three hours in the morning before you leave for work and another 5 hours in the evening.
Give your pool a good shock treatment 1 to 2 days before the storm hits. You can bring the chlorine level up pretty high to prolong the pool being depleted of chlorine.
It is recommended you have your water level between one-third and one-half up the swimming pool skimmer box opening. If the level is higher than that, it may slow or even stop debris from being pulled into the skimmer box through the plate or valve.
If pool owners or maintenance workers are constantly filling up the pool, there may be a leak. On average, swimming pools lose about a quarter of an inch of water each day, yet variations in wind intensity, humidity and sunlight can drastically change water loss rates.