As the summer rolls on along in Sarasota, Florida - we’ve all become acclimated to the daily late afternoon rainstorms. As much as our lawns and plants need the water after sitting in the hot summer sun all morning long, our pools do not. As we discussed previously about how the heavy rains can throw off your pool’s chemistry, now is the time when it can be critically important to keep on top of the situation. Some rain may be very acidic, therefore affecting both the alkaline levels and the pH of your pool water. When heavy rains fall that have a pH of about 5.0, it can result in lowering the pH balance of your pool – which should always stay at a balance of between of 7.4 to 7.6. It is when this happens that some Central Florida and Orlando area residents may experience GREEN swimming pool “syndrome”. If not taken care of right away or immediately, the pool algae can get out of control very, very quickly. The following are the reasons why your pool turns green and what you can do to get it back to being swim-ready and sparkling.
Why Do Pools Turn Green?
As more rainwater fills your swimming pool, the chlorine levels become diluted. When the chlorine in a pool goes below 1 ppm (parts per million), algae has the perfect scenario to start growing. Once the algae grows it will begin to change color, which is when you’ll first begin to notice that greenish tinge in the pool water. The moment you see that greenish color, you need to take action immediately, taking the necessary measures to correctly treat your pool before it gets out of control. Many times, simply super-chlorinating, or “shocking” your pool is enough to kill and get rid of the algae. To shock your pool for regular upkeep, you’ll typically need one pound of granular chlorine for every 10,000 gallons of water. If your past this point and dealing with an algae infestation, it’s going to require a lot more work and is beyond the point of just regular prevention.
The 3 Colors You’ll See and What They Mean
- Teal – at this phase of color, the algae is at its least problematic stage. In order to remove the teal color from your pool, you’ll need two (2) pounds of chlorine shock for every 10,000 gallons of water that is in your pool.
- Green (swamp-like) – seeing a swamp-like color in your pool is a slightly bigger issue, but luckily still fixable. To remedy a green, swampy color, requires three (3) pounds of chlorine shock for every 10,000 gallons of water that your pool holds.
- Black – if you’re seeing black, it’s the most serious of algae colors. Black pools require more work and you’ll need at least four (4) pounds of shock for every 10,000 gallons of water. You may also want to consider calling in a professional pool maintenance company.
How to Shock Your Pool
Before anything else, the first thing you need to do is test the chemicals in the pool water to make sure that the pH level is between 7.4 and 7.6 and that the alkalinity is between 100ppm and 150ppm. Shocking your swimming pool should be done at night, and you will also need to keep the pool’s filter running the entire time. After you’ve tested the chemicals you:
- Pour the bag of calcium hypo-chloride (shock) into a bucket of pool water.
- Pour the contents of the bucket into the water around the perimeter of the pool.
- Leave your pool filter running and see what the pool looks like in the morning. If it’s still discolored, then you’ll need to repeat the process with a second shock treatment.
Stay in Control! Prevention Is Key:
You may notice that after you shock your pool, the green color will go away, but your pool will look cloudy. This means that the chlorine is doing its job, but you need to continue to keep the filter running for 24 hours at this point. It’s also important to keep an eye on the filter pressure to prevent a rise. If you see that the pressure has risen by approximately 20-25%, you’ll then also need to clean or backwash the filter. After the cloudiness fully clears up, you can then reduce the filter’s run time down to only 15 hours a day.
Make sure you keep testing the pools chemicals to make sure the pH and alkalinity are within the correct range (pH between 7.4 and 7.6; alkalinity between 100 ppm and 150 ppm) and that the chlorine level is staying between 1 ppm and 3 ppm. You’ll need to continue balancing your pool’s water weekly afterwards, until everything is back to normal. At this point you can once again resume running the filter for 10-12 hours a day. You may additionally want to consider adding an algaecide to your pool weekly to keep it sparkling for the rest of the summer.