What You Need to take care of a green pool water problem:
- A deep Leaf Net
- Sturdy pool brush- make sure your bristles are still strong and all there
- Pool Acid – 3 Gallons
- Calcium Hypochlorite (Granular Pool Shock) – 5 pounds
- Pool Bleach – 10 Gallons
- Check your Cartridge Filter Element for Need of Replacement
- A pool water test kit
Before handling pool chemicals, wear gloves, protective eyewear, and clothing that covers exposed skin. Follow product-label directions, use chemicals in a well-ventilated outdoor area, and never mix pool chemicals together.
Know What Type of Pool Algae You’re Dealing With
Not all algae behaves the same way. Green algae is the most common type and can spread rapidly when sanitizer levels fall or circulation and water chemistry are out of balance. If you are dealing with a green pool, treat it promptly before the bloom becomes harder to control. Yellow or mustard algae often appears as a yellow-brown coating in shaded areas and may cling more stubbornly to surfaces. Black algae can be especially difficult because it can establish itself within porous pool surfaces, making surface-level treatment less effective. Learn more about preventing black algae before it becomes a recurring issue. If black algae or another algae problem keeps returning after proper cleaning and treatment, professional water testing and inspection can help identify the underlying cause.
Step 1 Remove Debris
If your pool is full of organic material it will take more chemicals and time to turn it around. First, we recommend using a deep, sturdy leaf net vs. a shallow leaf net that only cleans floating leaves off the surface. They won’t be sturdy enough to pull debris from the pool floor which is key in getting your pool back to swimming condition. Have a trash can(s) nearby for the debris to ensure that they don’t end up falling back in your pool.
Step 2 Add Chemicals
Your pool is probably a green cloudy mess, so you’ll want to add two chemicals to begin the clearing process:
- Pool Acid – also known as Muriatic Acid
- Pool Bleach (bought in the big yellow jugs) also known as Sodium Hypochlorite
It’s important to wear eye protection, appropriate clothing, and gloves to protect your skin when dealing with these two chemicals.
First, add 1.5 gallons of the pool acid to the pool. The goal of the pool acid is to drive down the pH of the water so that the chlorinating compound will be effective. As a tip, pour the acid slowly behind you into the pool while walking on the poolside. Be aware of the pool deck and surroundings to avoid spilling the acid. Once the acid is added triple rinse the one empty jug putting the first two rinses in the pool.
Next, add the pool bleach. The jug should have an air cap (small cap) and a dispensing cap (large cap). Remove both and pour into the shallow end of the pool. Repeat with three whole jugs or 7.5 gallons of pool bleach. Follow the same precautions with eyewear and gloves, avoid splashes and rinse any area that gets bleach on it thoroughly with water. Rinse the jugs at least twice with the first rinse going back in the pool.
Once the chemicals are in, it’s time to get the water moving. If your pool has a recirculate mode on the multiport that’s what we want. With the system off, put the multiport to recirculate and turn on the system. This will bypass your filter and just move the water.
Step 3 – Circulate & Brush
If you have a cartridge filter element, you can watch our video to see how to properly clean your cartridge filter element. You can achieve similar results in recirculating by removing the cartridge filter and running your system without it.While you let the chemicals work, we suggest you clean your old cartridge element even if you end up replacing it. Set both the new one and the old one aside for use later.
After about 30 minutes of water circulation with the chemicals in the pool, brush the pool floors and walls. Your brush should be in good shape and strongly backed with metal. Pay extra attention to corners, steps, ladders, grout lines, and other areas where algae can remain attached. Once treatment has killed the algae, proper filtration becomes important for removing suspended particles and restoring water clarity, so monitor the filter closely as cleanup continues.
Expect your pool to turn into a cloudy green/blue mess but do your best to brush everything – floors, walls, and steps, even though you can’t see. When you are done brushing turn the system off at the breaker so the water doesn’t start circulating accidentally.
Step 4 – Add More Chemicals
Add the rest of the open acid container approximately ½ gallon, and then broadcast 3 to 4 pounds of granular calcium hypochlorite over the bottom of the pool. To distribute, you should open the bags into a clean dry bucket and with a gloved hand broadcast (throw underhand sideway away from you like throwing a Frisbee) the granular product across the pool so it sinks and covers the pool floor. When done, double rinse the bucket and gently pour the rinses into the pool, try not to disturb the settling calcium hypochlorite. Now we want the pool to settle out so the best thing to do is leave your pool overnight and let the chemicals to do their job.
Step 5 – Evaluate Your Pool Water
You’ll need to evaluate your pool the morning after adding chemicals, so go take a look at your pool. Your pool might look like one of these photos. Brush a small spot to see if the Algae is dead. It comes up in a cloud if it’s dead, it streaks in place if it’s alive.
As long as the Algae is dead we move forward. “how to vacuum the pool with green algae?” If the algae is still alive you need to go back to Step 2 and repeat the process (you may need to buy more chemicals). If this happens more than once, having to go back and not killing the algae, you need to stop and call a pool service professional to come test your water to determine your next steps.
A severe algae bloom may take about 24 hours to several days to clear, depending on how much algae is present and whether treatment must be repeated. Once the algae is dead and has settled, vacuum the dead algae from the pool and clean or backwash the appropriate filter as needed. Continue testing the water as clarity improves, and get professional help if the algae remains active or quickly returns.
How to Help Keep Pool Algae From Coming Back
After the pool clears, retest chlorine and pH and keep water chemistry within the appropriate range for your pool. Heavy rain can dilute sanitizer levels and introduce debris, while large swimmer loads can also change water chemistry, so check the pool after storms and especially busy swim days. Depending on your pool’s needs, shocking the pool may be part of restoring sanitizer levels after demanding conditions. Consistent circulation, brushing, debris removal, and filter care also make it harder for algae to gain a foothold. If algae repeatedly returns, additional water testing or professional evaluation may be more useful than repeatedly adding chemicals. Pool Troopers can help with routine pool maintenance to keep your pool clean, clear, and ready whenever family and friends want to swim.
