Vacuuming will not get rid of algae. You need to SHOCK the pool and actually kill the algae first. After that, you can begin brushing/vacuuming/getting your chemicals back in balance. I repeat, VACUUMING DOES NOT GET RID OF ALGAE!
Not recommended to use an autovac for algae. The speed of the vacuum stirs the algae into the water. Some of it may get caught in the screen, but most of it breaks apart into fine particles that blow back into your pool through the water jets that propel the vacuum.
To clean up an algae-covered pool without draining it, first, brush the pool walls and floor to loosen the algae. Next, shock the pool with a high dose of chlorine to kill the algae. Run the pool filter continuously and add an algaecide to help remove any remaining algae.
If your pool is still green after adding shock and waiting 24 hours, there could be several reasons for this: Insufficient Shock: You may not have added enough shock to effectively kill all the algae. The amount of shock needed depends on the size of your pool and the severity of the algae problem.
Vacuuming After Shocking
As mentioned, you should vacuum your swimming pool as much as possible to keep the job manageable. However, after shocking the pool, you shouldn't vacuum for at least 24 hours. Running the water pump during this period will allow the shock to do its job.
Before you start pouring shock in the pool, the first step is to brush the sides and floor of your pool to loosen all the algae. Doing this breaks the skin and allows the pool shock to more easily kill the algae. Once you've done this, it is important to make sure you have the proper pH level in your water.
Not only do you rinse the filter, you can easily vacuum the pool after that. This leads to a very clean pool. When you backwash the filter your pool will remain dirty for some time.
Let the shock try to fight the algae first. Add algaecide about 24 hours after shock to finish the job and prevent future algae blooms.
Algae are microscopic plants that can multiply rapidly when conditions are favorable, even in the presence of high chlorine levels. While chlorine effectively kills algae, high levels can sometimes become ineffective due to factors like poor circulation, pH imbalance, and organic debris.
Determine how severe the algae or other biological growth is. For heavy soiling, dilute 2 parts water to 1 part GK Greener Kleener. For light to medium soiling dilute 3 parts water to 1 part GK Greener Kleener. Easily apply the formula to the affected area using a garden sprayer or a brush.
There's a protocol when using Clorox® Disinfecting Bleach for swimming pool disinfection to prevent algae growth when a pool is in use: on an ongoing basis, if you super-chlorinate the pool with 6-12 cups bleach per 5,000 gallons of water, in addition to regular chlorination, algae growth can be prevented.
Use a pool brush to vigorously scrub any pool surfaces covered in algae, including the walls, floors and steps. Apply a green algaecide according to the directions on the label. Let the water circulate for 24 hours, then brush the pool surfaces again. Vacuum or backwash to remove any remaining dead algae.
Backwash/Clean the Filter Again
This step is CRITICAL! Not only does it remove the algae from your system preventing it from being recirculated back into the pool, but it also allows the filter to get right back to work in the next steps.
Vacuuming to waste is helpful when there is a lot of debris in the pool, especially silty dirt, that clogs up the filter quickly, requiring you to stop vacuuming to backwash or clean the filter.
When algaecide treatments are applied incorrectly, one potential result is foaminess in the pool. Even high quality copper-based and silver-based algaecides will cause foamy pool water, if too much is applied.
After clearing algae
When: Use a water clarifier after you've killed an algae bloom as it'll help to coagulate dead algae particles in your pool water.
Is it possible to shock your pool too much? Yes—excessive shocking of your pool will keep it at an elevated chlorine level. This will cause irritation of the skin and eyes as well as excessive wear and tear on your pool filter system, including excessive corrosion of all metal parts.
It's all to do with your pool's pH. Pool expert Rafi Friedman told me that 'Pool shock works best with a balanced pH. If your pool's pH is too high or too low, the shock won't be effective. Ideally, your pool's pH should be close to neutral, around 7.2-7.4, before shocking.
Turn on the pump and allow the sand filter to backwash for 2-3 minutes or until the water in the sight glass (typically located on the top of the filter) is visibly clear. How long you backwash the sand filter for is not critical though you should visibly see clear water within 2-3 minutes.
In some cases, the filter grid may get damaged and let the D.E. powder and dirt pass through the filtering. The dirt will come back into your pool and in such circumstances, you should open up the filter and check it.