What Effect Does Rain Have on The Water in My Swimming Pool?

    When you think of factors that can affect your swimming pool’s water quality, rainwater may not be at the top of your list, but it can wreak havoc on your pool’s chemistry balance in more ways than one. Here is everything you need to know about rainwater and how it affects your pool water.

    What problems can rain cause in my swimming pool?

    It’s not so much the rain itself that’s the problem, it’s the contaminants that it brings with it that’s the bigger issue. For rain alone to affect your pool, it needs to be a heavy downpour. This will dilute your chemicals and throw out the delicate balance. Pollution in the air often carries microbiological organisms, including bacteria, and this can make rainwater acidic. Clouds can contain heavy metals, and when there is heavy rain and wind, organic matter such as leaves, and other debris will end up in your pool. None of which are good for the water.

    When there are more contaminants in the water than the chlorine can manage, the chlorine binds to them and this makes chloramines. Once your free chlorine turns into chloramine, it is unable to sanitise the water properly. The leaves and other organic matter that has fallen into your pool will start to decompose, this will affect your pH levels, and your pool may start to go green. Along with affecting your chlorine and pH levels, rainwater can disrupt your (TDS) total dissolved solids levels, calcium hardness and alkalinity, to name a few.

    The extra water in your pool can prevent your circulation system from working to its full potential as it can stop the skimmer door from closing and as a result, debris cannot be contained in the skimmer. If the debris is left in the pool to float around, it will inevitably sink to the bottom and start breaking down.

    How do I empty my pool if it’s too full?

    Lowering the water in your pool is simple, here’s how:

    1. Switch your pump off.
    2. Turn the multiport lever on your pump to waste.
    3. If you have valves on the waste line, open them.
    4. If you have a skimmer plate attached to your skimmer box, remove it.
    5. Disconnect your cleaner.
    6. Switch the pump on again and wait until the water has receded halfway down the skimmer mouth. Don’t leave and come back as it empties rather quickly, and if you forget, you may come back to an empty pool.
    7. Turn the pump off again and rotate the lever back to the filter setting.
    8. Replace your skimmer plate and reconnect your cleaner.
    9. Turn the pump back on.

    Does it matter if I’ve emptied the pool too much?

    Yes, a low water level is just as detrimental to your pool equipment as a high one. If you have emptied the pool a little too much, you’ll have to refill it with a garden hose until it’s back to where it should be.

    Cleaning your pool after a heavy downpour or continuous bouts of rain

    If you have had a lot of rain or a heavy downpour, you should follow the steps below to ensure your pool water isn’t significantly affected.

    Clean the pool

    The first step is cleaning out the pool. Remove any leaves and debris using your pool scoop. Run your automatic or manual pool cleaner to pick up smaller particles that were missed with the pool scoop and empty your skimmer basket.

    Test the water

    Once your pool is clean, you will need to test the water to check if any of your chemical levels are unbalanced. You can do this by taking a sample of your pool water to your local pool shop, or you can do it yourself with a water testing kit. If you are taking your sample to a pool shop, they will be able to tell you what your pool is missing or has too much of, and they can give you advice on what chemicals you need and how much to use. If you are testing the water yourself, the test strips will give you an instant indication of your chemical levels and whether any of them are off or not.

    Here the most common chemicals that are affected by rainwater and the levels they should be:

    Chlorine – Normal chlorine levels should be between 1-3ppm.

    Ph – Ideal pH levels are between 7.4 to 7.6.

    Total Alkalinity – A TA range of 80-120 ppm is optimal.

    Calcium Hardness – CA levels should be from 100-300 ppm.

    Total dissolved solids – Aim for TDS levels from 1500ppm to 3000ppm.

    What do I do if my pool is brown?

    It’s not uncommon for a pool to turn brown from excessive rainfall. The water has nowhere to go once the ground is completely drenched, and it will fill up garden beds and flow over retaining walls into the pool. This excessive water brings with it dirt, foliage, mud, and other unwanted nasties. If your swimming pool is brown, you can clear it up by using a floccing agent. A floccing agent works by bonding the floating dirt particles together. They will then sink to the bottom. This makes it far easier for your pool cleaner to pick them up.

    What if my pool is green?

    If contaminants haven’t been cleared from your pool quickly, it’s a high possibility that your swimming pool will turn green, if the weather is particularly warm, it may happen at an even faster rate. To fix a green pool, you’ll need to shock it. This is the process of adding a high dose of chlorine to your pool. Along with your shock, you’ll need to add an appropriate clarifier, oxidiser, algaecide and ensure your pH levels are balanced correctly. It’s best to do this late afternoon as the sun’s UV rays break down chlorine and prevent it from working to its full potential. Run your pump overnight to ensure the chemicals are moved throughout your pool water. You will notice a considerable difference in the water come morning.

    Invest in a pool cover

    Rain is good for many things, just not our pools, however, you can minimise the effects it has on your pool water by investing in a good quality pool cover. They are a good idea for many reasons, not just to prevent rain disruption. They can drastically reduce chemical, heat, and water loss by up to more than 70%. They come in many different price points, and there are options to suit every budget. Hardtop covers are the most effective, but they are also the most expensive.

    As mentioned, infrequent rain showers are unlikely to place any burden on the quality of your water, it’s the heavier rains and impurities that rain introduces to your pool that can turn your water from crystal clear to murky and unpleasant. The colour change in your water can be noticeable within a few hours after heavy rain. If you are having troubles with your water after rain, or if you have any questions about pools in general, just ask our friendly team here at Barrier Reef Pools or visit the website. We are happy to answer any questions you have.