What is a good pH level for a pond?
pH is a measure of whether water is acidic or basic. Fish have an average blood pH of 7.4, so pond water with a pH close to this is optimum. An acceptable range would be 6.5 to 9.0.
A safer, longer lasting way to reduce high pH is to add carbon dioxide, which acts as an acid in water. Carbon dioxide levels can be increased by adding organic matter such as cracked corn, soybean meal or cottonseed meal to ponds. As organic matter decays, it releases carbon dioxide.
In cases where the pH is too low (5.5), the fish can experience a condition known as Acidosis, which can kill a fish in just a few days. In cases where the pH is too high (9.5), fish can experience a condition known as Alkalosis, which can also be fatal. Note: Koi do not like extreme pH changes.
The higher pH means the water is becoming alkaline, and the cause for the rise is often substances leaking into the water from the ponds surroundings. A higher water pH can become especially dangerous for pond fish, as both high pH and high temperatures will increase the toxicity of ammonia in water.
A pH level too high will result in more alkaline water which often wrecks havoc in managing the water clarity and often results in green water and algae growth.
The acceptable range for fish culture is normally between pH 6.5 and 9.0. Fish will grow poorly and reproduction will be affected at consistently higher or lower pH levels. Very high and very low pH values, respectively, greater than 9.5 and less than 4.5, are unsuitable for most aquatic organisms.
Areas or periods of heavy rainfall or snow also cause pond pH crashes. Natural rainfall is slightly more acidic (with a pH averaging 5.6) than normal range of stream water. Which would have a neutral pH reading around 7.0. Thus, large amounts will alter a pond's pH.
You can raise the pH with baking soda.
1 teaspoon of baking soda for every 8 gallons of water should do the trick. Michael can mix some pond water and baking soda in a bucket to let it dissolve.
What causes a pond to become acidic with a low pH? Carbon Dioxide gets into all ponds from the air. When it reacts with the water it forms Carbonic Acid which lowers the pH. If you live in a hard water area the water will be more alkaline which is good.
Algal abundance is affected by pH. In one study when the pH was lowered from 6.6 to 5.0, algal abundance increased (Leavitt 1999). Because an increase in algal abundance was observed when lowering the pH, it can be expected that algal abundance should decrease when the pH is raised.
Can low pH cause algae?
Lastly, but certainly not least, the presence of low pH in your pool will greatly decrease the amount of working chlorine, which can lead to bacteria and algae build up.
Mix baking soda into a serving of water to change the pH and alkalinity. Pour yourself 1 cup (240 ml) of water and pour in 1 tsp (4 g) of baking soda to raise the pH by 1. Stir the solution together thoroughly to bump up your pH levels to make alkaline water.

High pH levels in the tank will cause fish to show excessive excitement, scratching, and trying to jump out of the tank. If the problem is not solved, they will start showing signs of disease, such as white spots on the body and bloody fins, which are signs of ich.
However this is where many people start to add too much air, it won't do any harm but it can be unsightly seeing a Jacuzzi type water swirl, and most of the air evaporates back into the atmosphere rather than dissolving in the pond water.
If there are no plants or fish in the pond, simply add 1 gallon of white vinegar for every 200 gallons of water. Allow it to sit for three days, and then drain the pond and refill with fresh water.
We recommend feeding your fish once a day. However, some fish owners will like to do it twice a day but feed in smaller portions, instead of feeding all their food in one massive clump. The amount of times you feed your fish is a preference as long as you feed them the correct amount.
Increased air contact results in higher and more consistent levels of oxygen in the water – a key component of a healthy aquatic ecosystem. Wind, heavy rain and waterfalls are natural sources of aeration in a lake or pond.
Baking soda should only be used in the pond for scrubbing stains or algae deposits on an exposed pond liner while the water is drained. A small amount left behind from this kind of cleaning won't hurt any fish in the water or have a strong effect on the pH.
Many fish species like tetras, rasboras, Discus and L-number catfish like and appreciate a low pH.
A substance with a measurement of 0 to 6.9 pH is acidic, while a pH of 7.1 to 14 is considered alkaline. Most aquarium fish thrive in pure water, which is a neutral pH of 7. A tank with high pH, meaning it's very alkaline, is dangerous for fish and their habitat.
What happens to fish is the pH is too low?
Low pH reduces your fish's ability to swim, eat, reproduce, and grow – everything it must do to survive. If your fish become stressed, they will seem sluggish, often sleeping more than usual.
Carbon dioxide in the water causes the pH to drop. By exposing your tap water to the air and agitating the surface, you are causing a gas exchange at the surface of the water (oxygen goes from the air to the water while carbon dioxide goes from the water to the air).
Explanation: pH of a substance can be increased by adding basic substances to it. The most common one would be to put limestone or quicklime into it. Those two compounds are alkaline or basic, and will therefore reacting with the acid in the lake to neutralize it and form water, which has a higher pH than the acid.
If you want to increase the pH of water, you must add an alkaline substance to it. The pH scale ranges from 0 to 14, with anything above 7 being alkaline, and anything below 7 being acidic. Sometimes, water softeners are recommended for people who want to increase the pH level of their drinking water.
The preferred way to lower the pH in freshwater aquariums is to use natural methods such as adding peat moss, driftwood, and catappa leaves. However, other solutions such as using carbon dioxide (CO2) reactors and reverse osmosis are also commonly used.