swimming pool is green what do I do
Pool Knowledge

Swimming Pool Is Green What Do I Do?

Keeping your swimming pool water clean and clear is advisable. My swimming pool is green what do I do? This is a question we’ve found most pool owners asking after their pool water turned green. We are here to let troubleshoot the problem causing your pool water to turn green, clear your green water, and know-how to prevent such an instance in the future.   

Swimming Pool Is Green What Do I Do – What Is the Cause? 

A straight answer shall be algae. Algae is what causes the green color in your pool. Algae is caused by a chemical imbalance in your pool water, the more the imbalance, the more algae shall grow and the greener your water gets. 

A swimming pool with enough free chlorine discourages the development of algae, therefore, preventing your pool water from turning green. All the other pool chemicals might need balance if chlorine balance doesn’t work.  

To What Extent Is Your Pool Green?

This is the first question to ask yourself when troubleshooting the problem. If the pool is too green, then you have to opt for something else other than chlorine balancing. However, if your pool water is just starting to look green, then a simple chlorine shock that we describe later shall work.

Some pools get dark green, especially when opening them up for summer. In such a case, trying to balance the chemical concentration shall do you no good. What you shall have to do here is drain your pool then acid washes it and refill it with clean water again. This shall be expensive and labor-intensive, however, better take the sword by the edge when you know nothing else can work.

To determine the extent of algae concentration in your pool, check how far you can look into the water. If you can see beyond 6 inches into your pool water, then treating shall work. If on the other hand, you can only see a dark green surface, then it’s time to drain, wash, and refill.

Now, Test Your Water   

Since the pool is green, we already know the problem is chlorine deficit. What we should therefore test is the pH of the pool water. In case of a very high pool water pH, the water shall turn cloudy upon shocking. 

It’s obvious that after shocking, your pool water shall turn cloudy for sometime before filtration, however, with high pH, the cloudiness shall intensify causing another problem.

Testing your water can be easily done using a quality test kit, however, a test strip shall also do fine. Check your pool water alkalinity and if the pH goes above 7.2 then you have to lower it. To do this, add muriatic acid, one falling shall be enough to balance your pool water pH. 

A low pH shall work best for shocking, however, it might be too acidic for swimming, ensure you confirm the levels after shocking.

My Swimming Pool Is Green What Do I Do? Shock Your Pool 

Granular chlorine shall help you shock your pool as a means to combat the spread algae. You shall need a lot of chlorine here, about five pounds. It is therefore advisable that you buy a 25-pound pack since it shall be cheaper. You’re not going to use all of it now, however, your pool is there to stay and shall need chlorine in future.

Prepare five pounds of granular chlorine. Turn on your filter pump and spread the chlorine along the edges of your pool. Let it spread evenly on your pool surface while your pump filter system circulates it in the water. 

After some hours of circulation, add an algaecide and a flocking agent.

Now give it time to get your pool clear again. The length of time it shall take for your pool to become completely clear shall depend on a number of factors. The prime one is the type of filter you’re using.  

Now turn on your filter.

Depending on the type of filter you have, the cloudy form of your pool water shall take a week or more to clear. Again, if you have a faulty filter, your pool shall never get clear unless you repair the filter. This is because the filter is what removes the algae deposits that make you look water to look cloudy after shocking.

For a DE filter

Prepare your DE filter by backwashing it and adding fresh DE powder. Clear the drain of your pool to ensure that the algae deposits shall move out. After your filter is serviced, turn it on and shock the pool as previously guided. Let your filter continue running for a day.

For a sand filter

Backwash your sand for more than six minutes. After this, clear your pool drain as explained on the DE filter. Turn on your sand filter pump and let it run for a day. It might take longer, more than a week, to get your pool clear. Just trust the process.

For cartridge filters

Clear the cartridge at least two times a day for two days. This is because we expect a lot of waste which might clog the cartridge. It is advisable that you be checking your cartridge more often and clean it until your pool water turns clear again.

The next step is to filter and brush stubborn points.   

There are stubborn points of your pool that shall remain green. Use a brush to scrub off the green parts. Since your pool shall still be cloudy, let the filter run until your water gets clean and clear. If the cloudiness takes too long to clear, then your filter might have a problem. Check and repair it then continue with the process.

If your pool persists to be green, then there might be an imbalance of other chemicals most probably the stabilizer. 

My Swimming Pool Is Green What Do I Do? Conclusion   

Depending on the extent of the green in your pool, you can either drain and acid washes it or just shock it. Shocking comes in handy when your pool isn’t that green. For a dark green pool, draining is the best option. Your filter should be running during and after the shocking process. You just got your pool water clear again!