Only algaecides can "kill" algae in pool water. However, baking soda can help clear up algae. Use both so you can restore sparkly, clean water!
A rule of thumb is 1.5 lbs. of baking soda per 10,000 gallons of water will raise alkalinity by about 10 ppm. If your pool's pH tested below 7.2, add 3-4 pounds of baking soda. If you're new to adding pool chemicals, start by adding only one-half or three-fourths of the recommended amount.
Chlorine is still one of the most effective killers of algae so doing a super-chlorination of 10-20 ppm of chlorine can go a long way towards wiping out the algae. Liquid chlorine is an ideal shock for algae because it is fast acting and does not add cyanuric acid (CYA) or calcium to the water.
You can use baking soda in a pool for two primary purposes: to increase the alkalinity and pH level for clear water and to cure black algal outbreaks on your wall. The founder of Cleaning Green LLC, Alicia Johnson, explains that baking soda (or sodium bicarbonate) has a pH level of 8, meaning it is a natural alkaline.
Cooksey said baking soda may work because it gives algae extra carbon dioxide necessary for its metabolism at a key point in its life cycle. If the baking soda is added too early or too late, the algae don't respond.
Another chemical-free solution that you can consider is a mixture of baking soda, water and vinegar. Add two parts of white vinegar to one part of water and three heaped spoons of baking soda. Dip a scrubbing brush into the mixture and apply it to the algae stains on your furniture. Leave it for about ten minutes.
Barley straw is a natural way to fight algae. On contact with water, the straw starts to break down, and as it does so it releases peroxides into the water which combat algae. Available in mini bales, or as a concentrated extract of barley straw liquid, it's a natural way of chemically fighting algae.
Adding shock to your pool super-chlorinates your water. And this extra dose of sanitizer will kill algae growth. The more serious your pool algae problem, the more shock you'll need. We recommend using calcium hypochlorite shock, or cal-hypo shock, as an effective algae treatment.
However, adding too much baking soda might also raise the PH level of your pool to an undesired stage (alkaline). In the case where too much baking soda is added to hard water, it can cause a build-up of calcium around your pool.
Allow the baking soda to circulate in the pool for at least 6 hours. Be sure to turn on the pool's pump to help it circulate more thoroughly. Test the pH and alkalinity levels again. Repeat the steps above if levels are still too low.
Hardware stores and home centers sell products designed to kill moss and algae, but you can save money by using inexpensive chlorine bleach or a non-creamy hand dishwashing detergent, such as Dawn.
Apply a mustard algaecide following the label directions. Allow the water to circulate for 24 hours. Use a pool vacuum or backwash the pool again to remove the remaining dead algae. In persistent cases, brush the pool and apply algaecide once more after two to four days.
“Adding too much baking soda to a pool will cause the alkalinity to rise,” Vernon says. Anything above 120 ppm is too high. And over-alkaline water, he says, “can create scale build-up and cloudy water.” So as you add baking soda to adjust pH and alkalinity, remember to be patient.
When added to water containing algae, H2O2 breaks down into water and oxygen, releasing free oxygen radicals in the process. These free oxygen radicals can then react with and destroy the cell walls and membranes of algae cells, causing them to die off.
Whenever pH drops below 7.2, add 3- 4 lbs. of ARM & HAMMER™ Baking Soda per 10,000 gallons of water to raise the pH. If after a day or so, the pH has not stabilized and drops below 7.2 again, add another 4 lbs. of ARM & HAMMER™ Baking Soda per 10,000 gallons of water.
Does baking soda kill algae in pools? Only algaecides can "kill" algae in pool water. However, baking soda can help clear up algae. Use both so you can restore sparkly, clean water!
Shock Your Pool
Shocking is the process of adding chemicals to your pool to raise chlorine levels and kill bacteria and algae. We recommend using a calcium hypochlorite shock to treat your algae problems.
In the same way that baking soda can be a spot treatment for black algae, household borax does the same for blue and green algae. Simply use the borax to scrub away algae that's sticking to your pool walls, then use the brush to dislodge it. Follow up by vacuuming up or scooping out the free-floating algae.
When temperatures reach below 40°F algae growth is stopped, but it can still survive and become dormant over the winter. Pool algae will come back to life weeks before you decide to open your pool.
Mix two gallons of water, two cups of oxygen bleach, and one cup of borax. Stir the recipe until everything dissolves. Add ¼ cup of dish soap and stir. Apply the cleaning solution and scrub with a brush.