Since baking soda is highly alkaline and reacts when mixed with an acid, many people assume it can be used to change the pH of a pond to discourage algae growth. However, even a large amount of baking soda dissolved in a pond will have little to no effect on either algae or pH.
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.
Barley straw. 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.
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.
Floating plants, such as lilies and lotus, provide shade and reduce direct sunlight in the pond to control the growth of algae. Add submerged plants that release oxygen to the water, such as anacharis, hornwort and parrot's feather.
Blue/Green Algae
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.
A build-up of organic matter (sludge) on the bottom of the pond. Fertiliser leaching into the pond, perhaps from overfeeding a lawn. Pond debris, such as fish faeces, fallen leaves and invasive pond weeds. Filling or topping up the pond with mains water – use rainwater whenever possible
Bleach is great for killing algae (and other organisms that may lurk in your tanks) and for keeping it from coming back.
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.
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.
Vinegar is acceptable to use for killing algae and cleaning a pond when it is drained. The acidic is good at lifting away the stubborn algae deposits and stains without damaging the liner material. When used in this way in limited amounts, the leftover vinegar residue won't hurt the fish or change the pH of the water.
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.
Hydrogen peroxide is especially effective against green algae and blue-green algae (cyanobacteria). It is heavier than water and sinks to the ground, which is useful if you're dealing with algae near the ground and somewhat of a hindrance if the algae are higher up in the tank.
Yes, dilute apple cider vinegar (ACV) is a great choice for combatting algae in your bird bath the natural way. The higher pH value of the ACV makes it too acidic for algae to grow.
One of the best algaecides out there that is safe for fish is a peroxyhydrate granular algaecide (which comes under many brand names). This comes in a solid granule form, and when added to pond water, it oxidizes, which destroys algae growth!
Keep the Pond Aerated
Aeration devices are a useful way to increase the amount of oxygen in your pond that helps beneficial bacteria to break down and eliminate green water algae.
StoneCare4U Essential Algae Remover is a safe and easy way to remove algae from any 'hard' external surface. Its biodegradable formula can be used on a multitude of outdoor surfaces including paving, walls and roof tiles.
4) In a container, combine 1 cup of detergent and 1 litre of water. Rub the solution through any remaining algae spots with a scrubbing brush. 5) You can clean the remaining surface using the pressure washer. If some algae remain, carry on with the rest of the steps.