It’s not funny to open the pool cover and see that the water has turned green and swampy. This means that algae has temporarily taken over your pool and you will need to thoroughly clean and treat it before swimming. Read on to find out how to get rid of the dreaded green water.
Part 1 of 3: Preparing for Pool Treatment
Step 1. Check the pool water
Use a chemical test kit to test chlorine levels and determine the magnitude of the problem. When the chlorine level drops below 1 millionth dose, it will cause algae to grow in the pool, turning the pool water green. When this happens, it is necessary to "shock" the water with chemicals to kill the algae and return the pool water to normal chlorine levels.
- Proper pool maintenance, including the availability of working filters and making sure the pool's chlorine and pH levels remain stable, will prevent algae growth in the first place.
- Algae is constantly growing, so by allowing the pool to be unattended for even a few extra days, you can create a green pool situation.
Step 2. Balance the pool chemicals
Before treating the pool, balance the pH by adding either acid or base in order to bring the level to 7.8 immediately. The level you usually want to see in your pool is high on the scale, but it is necessary when you are treating algae. Here's how to balance the pH:
- Turn on the pump to circulate the chemicals throughout the pool.
- Adjust the pH by either increasing the pH with sodium carbonate or decreasing it with sodium bisulfate solution.
Step 3. Make sure the filter is working properly
Clean out any leaves, sticks, and other debris that might clog the filter. Backwash the filter if necessary and make sure it works well before adding chemicals to the pool to kill algae. Set the filter to run 24 hours a day so that it filters out any algae during the cleaning process.
Step 4. Rub the sides and bottom of the pool
Use a pool brush to scrub the pool well before adding any chemicals to the water. Algae will cling to the surface of the pool, but cleaning will remove it. Scrubbing also helps cleanse the algae, allowing the chemicals to work faster.
- Clean especially well in areas where algae can be seen. Try cleaning the whole thing so that the pool is thoroughly cleaned.
- If you have a vinyl pool, use a nylon brush. Brushes can damage vinyl pools, but they can be used safely on gypsum pools.
Part 2 of 3: Shocking the Pool
Step 1. Treat the pool with a shocker
The shocker has high chlorine levels, which kill algae and disinfect the pool. Choose a powerful shocker with about 70% active chlorine, enough to handle tough algae and bacteria. Follow the directions on the stunner packaging to use the correct amount for your pool water.
- If you have a large amount of algae in your pool, you may need to process it several times to keep the algae from blooming further.
- The water may look cloudy or dirty when you add shock, but as the water passes through the filter, it will begin to clear.
Step 2. Treat the pool with algicide if the chlorine drops below 5.0
Let the algaecide run in the pool for at least a 24 hour period.
Step 3. Prevent pressure build-up in the filter by cleaning frequently to remove dead algae
When the algae dies, they will fall to the pool floor or float in the pool water. They will also lose their green coloration.
Part 3 of 3: Shutting Down
Step 1. Vacuum the dead algae left in the pool
Use the brush again to clean the bottom and sides of the pool, then vacuum out any dead algae. If there are a lot of dead particles and you are having trouble vacuuming, you can add a flocculant to help the algae bond together and make vacuuming easier.
Step 2. Let the filter work until the algae disappears
Your pool of water should be crystal clear after treatment. If the algae seems to be reappearing, go through the shocking and processing process again until everything is cleaned up.
Step 3. Recheck the chemical levels with your pool test kit
All chemical levels should be within the normal range.
- Wear old clothing when using pool chemicals. If chlorine spills or drips onto clothing, it may discolor.
- You can take a water sample from your nearest pool store on a monthly basis and get a computer analysis. This will help you get rid of water problems in your pool early on.
- Use a pool net daily to remove leaves and other floating debris from the top of the pool. It is much easier to remove debris from the top before it settles to the bottom.
- Keep chlorine levels between 1.0-3.0 ppm to prevent algae from growing in the pool.
- Do not add any chemicals to the pool unless you know what you are doing. Adding the wrong chemicals will create additional problems.
- When mixing chemicals in a pool with water, use caution. Always add the chemical to the water.
- Never mix chemicals together.
- Be extremely careful when handling chlorine. It can cause sore throat, coughing, or irritation to the skin, eyes, and lungs.