Mon-Sat: 9am-6pm
Sunday: 10am-5pm


Mon-Fri: 8am-5pm
Sat-Sun: Closed

A Guide to Clearing Algae Problems

Is your pool clouded or covered with unsightly green algae? If your kids would sooner head down to the nearest swamp to play Marco Polo than dive into your pool, it’s time to take action. Here are some maintenance tips prepared by the experts at Purewater to help you clear your algae problem.

Clean Debris

Did you know that organic debris like leaves acts as a food source for algae? There’s no point trying to address an algae problem if your pool is basically a giant buffet fueling the problem. Use a net or vacuum to suck up the decomposing organic waste.

Adjust pH

Algae creates a vicious cycle. It causes your pools pH level to rise, and higher pH levels promote the growth of algae while reducing the effectiveness of the chlorine you add to try and deal with algae. This is why we recommend using pH reducer to adjust the pH back down to 7.2. Follow the instructions on the package and then wait three hours. Repeat this step if the pH is still too high.


Now it is time to shock the pool. If you are trying to kill algae, a non-chlorine, light, or blended shock won’t do the job. Instead, use a generous amount of concentrated HTH Extra.  Note that dosages for algae treatment are usually quite high so if your algae build up is really bad, expect to double or even triple the usual dosage. Leave your pool cover off until the algae situation clears up.


After an hour, add the recommended dose of Eclipse algaecide. Go right to the good stuff and don’t bother with weak “bulk” algaecides that won’t get the job done.

Brush the Pool

You didn’t think the pool chemicals would do all the work, did you? Brush the entirety of your pool surface to knock stubborn algae out of place and improve chlorine distribution to the algae spores. If you want to clear your algae problem, you need some elbow grease.


A stagnant pool will invite algae to start growing again, so you need to circulate and keep your pool pump running. Otherwise, chlorine won’t reach the algae that have built up in your pump, filter, and pipes.


You need to repeat these steps (with the exception of adding algaecide) until the algae are killed off.  It can require multiple, back to back treatments, so be persistent and don’t skimp on the products or the elbow grease.


If the algae still aren’t clearing up, pay us a visit at the Purewater water test lab.  Your pool may have high phosphate levels which means you need to add an agent like Phos-Free into the equation.  There can also be mechanical or filtration issues we need to look at. Our testing service and advice are always free

A Guide to Clearing Algae Problems

Clear Dead Algae

Remember we said that organic debris becomes food for algae? Well, dead algae is organic debris, so make sure you get rid of it quickly. Make sure to chemically clean your sand or cartridge filter with a strong filter cleaner solution to help avoid more algae blooms.

Chlorine & pH Levels

After you’ve removed the algae, keep your chlorine levels at or around 3 ppm and keep your pH between 7.2 and 7.4.  Make sure your solar blanket comes off on hot, sunny days and at regular intervals to let the pool breathe. Proper pool maintenance after you’ve cleared the algae will help keep the problem from recurring.

Monthly Testing

Just because you’ve dealt with one algae problem doesn’t mean you’re in the clear! Bring in a sample of your water to the store every month for a free, detailed analysis to make sure all your levels are in good order.

If you need any more assistance with pool maintenance or your algae problem still hasn’t cleared up, call us or come into the Purewater showroom — we’d be happy to help restore your home pool to its original beauty. Happy swimming!

Contact Us | 613-726-0099 | |