Everybody loves having a swimming pool, where they can take a dip when the mood hits. But, maintaining that crystal clear water isn’t always easy.

Upon inspecting the pool daily, one might find that the water’s turned a little cloudy, or there could be some algae growing. If you are away from the pool for a long time, you might be greeted by an algae-filled water body upon return.

Photo of green pool

A green pool isn’t a very pretty sight, so we shall walk you through the steps of how to resolve a green pool. At the same time, we’ll also include some tips for maintaining the clear blue waters of swimming pools in the future.

So, without further delay, let’s dive into the details into how to clean a green pool.

Steps to Clean Green Pool

1. Draining the Pool

Empty Swimming Pool

Although this is the most extreme step one can take, there are few other options left if the pool has turned dark green and borders on a blackish color. In such cases, it is always more effective to completely drain the pool and then treat the surface to an acid wash.

The general rule is, if one is able to see six to eight inches below the water’s surface, then a chemical treatment is a viable recourse to clean the pool. In the event that such visibility is obscured, then the pool-owner must take a call whether to continue chemical treatment, or opt for a complete draining.

2. Lowering the pH Level

Ph Test for Pool

Before setting out to lower the pool’s pH level, one must know what the current state is. Without getting into the specifics, we should inform you that there are numerous water chemistry test kits to help in this process.

If the chlorine levels are not low, the pool won’t have turned green. So, one might skip that step. But, when it comes to the pH level, it is optimum to try and have it below 7.2 for this process. Otherwise, the pool is likely to get cloudier over the next few steps.

Once users know the pH levels, using sodium bisulfate can help reduce it, and the method is easy. You simply need to follow manufacturing instructions while adding the product to the pool. Tests must be conducted again in a few hours to observe results.

3. Shocking the Pool

Add Chlorine

Once the pH levels are lowered, the next logical step is to introduce chlorine to the water - something the pool’s been severely lacking. Adding granular chlorine or super shock chlorine helps kill off the algae and bacteria almost immediately.

While most products provide specific instructions for how much chlorine to use, the safer measure would be 30 ppm or parts per million. After application, users are advised to use the testing kit to keep checking for the right balance.

4. Pumping and Filtering

Swimming Pool Filter

The pool’s almost ready to return to its sparkling self. But, you need to pump and filter the water so as to get the balance back. The filtering process depends on the kind of filter used. For sand or DE filters, cleaning to remove sediment and sand is the first step.

Some basic things to follow include shutting the pump, rolling out the backwash hose, and finally checking for closed valves in the waste line. Then, the multiport valve handle has to be turned to backwash, or the push and pull valve has to be slid in.

Following this, the pump has to be turned on, so the water can flow through the backwash hose or pipe. It usually takes two to three minutes for the water to become clear. Then the valve needs to be turned to filter again. Immediately, the better flow rate and the filter tank’s lower pressure becomes evident.

5. Flocking the Pool

Cloudy Pool Water

Even after doing all this, the pool might remain a little cloudy. This is mostly due to the residual microscopic particles which resist pool chemicals and are small enough to escape the filtration process. The best way to tackle this is by using flocculants.

The organic chemicals help to clump the debris together, so they can be vacuumed from the pool’s floor. It is bound to leave the water crystal clear.

6. Killing Algae

Algae in Swimming Pool

Algae can be very persistent. Despite many feeling that this step isn’t necessary, it is actually crucial if you wish to avoid repeating the same process in a week’s time. Since algae have a fast growth rate and can take over the pool, killing it is mandatory.

Using an effective algaecide makes it drop to the bottom of the floor. After you kill off the remaining spores, continued treatment is recommended to prevent the algae from returning.

Why Does the Pool Turn Green?

Now that you know how to treat a green pool, you should focus on the various reasons why the pool might turn green in the first place. After all, knowing the causes might help prevent them better.

Basically, an overgrowth of algae is the underlying common cause, but different factors could lead to said overgrowth.

1. Improper pH Levels

If the pH level is too low, there could be eye irritation and erosion of pool materials. On the other hand, if the levels are high, it won’t kill the algae and bacteria. Ultimately, pH levels being off-balance cause water discoloration.

2. Filter Clogging

If the filter doesn’t function properly, keeping the pool clean becomes a nearly impossible task. Apart from the continued growth of algae, there is a chance of bacteria or debris discoloring the water too.

3. Weather Changes

Since algae are more likely to flourish in warm and humid environments, it is advisable for you to be more vigilant when there is a change in weather. For example, summer months or monsoons would be ideal for algae to take over the pool.

Tips For Pool Maintenance

1. Maintain pH Levels

Checking the pH levels twice or thrice a week is advisable, as well as keeping an eye on the liquid chlorine in the water. Ideally, pH levels should be between 7.4 and 7.6.

2. Frequent Pump and Filter Checks

Since algae are more likely to grow in stagnant water, one must ensure the pumping system and filters are working to keep water moving. In this manner, organisms are skimmed off.

3. Using Pool Cover

Covering a pool when it is not being used keeps out a lot of debris and unwanted organisms. Further, it prevents the sun from supercharging the lingering algae spores.

4. Brushing and Vacuuming Regularly

A basic tip of pool maintenance is to scrub surfaces and vacuum the pool floors, to prevent the growth of dead bacteria and algae.

Final Words

Prevention is better than cure, so we recommend pool owners to follow the basic maintenance tips to keep the waters of the pool blue. But, in the event that algae growth cannot be stopped, then the simple step-by-step cleaning method should help the pool get back to normal.

Try the step-by-step guide above to cleaning your green pool, and let us know how well they work for your pool.

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