Algae Growth in Water Systems on Golf Courses
Water systems, especially golf courses, can be inundated with algae resulting in clogged filters, dirty retention tanks, partially filled pipe systems, and clogged sprinkler heads. The result is higher maintenance cost to clean filters, higher pumping cost due to increased pressure requirement and uneven water distribution, which my effect turf quality. The problem is especially acute when using effluent discharged from sewage treatment plants which is loaded with nutrients. High nitrate and phosphate concentrations are typical on partially treated wastewater, which can result in algal blooms. It may also contain undigested organic material, providing a food source for the algae.
Potassium Permanganate is effective treating a large range of algae and protozoan parasites including; Epistylis, Bryozoa (also known as the Polyzoa, Ectoprocta or commonly as moss animals), Trichodina, Costia, and Chilodonella. It also treats Gyrodactylus, and Dactylogyrus.
Potassium Permanganate, KMnO4, is a caustic alkali that breaks down to the permanganate ion (MnO4-) and Manganese Dioxide (MnO2) when placed in water. It is very reactive and will readily react with organic material. Permanganate kills parasites by destroying their cell walls through oxidation. Since it is so corrosive to organic tissue, potassium permanganate will expend its oxidative energy on available organic (algae, detritus, dissolved organic compounds, ect) material first.
Other chemicals and methods are available to kill the protozoa, however, potassium permanganate reduces much of the organic material to the gas carbon dioxide. This can reduce the issues with accumulation of dead free floating protozoa in filters and sprinkler heads. The remaining elements of potassium permanganate become potassium and manganese which are typical require nutrients.
Potassium Permanganate is provided in 330 pound drums or 55.1 pound buckets. A application rate of approximately 500 ppm is typically effective in destroying most algae growth in systems. This is approximately 4 pounds of potassium permanganate per 1000 gallons of water (about 5 cups of potassium permanganate).
The easiest method is if the potassium permanganate can be applied to a wet well. The potassium permanganate can be sprinkled into the wet well and allowed to dissolve for a few minutes. Potassium permanganate is highly soluble to about 5% and will go into solution quickly.
Turn on the pump and watch the most distant sprinklers (or lake fill line) for the tell tale purple color either through sprinklers or a lake-fill line. Monitor the color in the wet well and reapply as needed to maintain the purple color. Make sure all mainlines and laterals are filled with the potassium permanganate solution. Shut off all pumps and valves to let the potassium permanganate set overnight oxidize the protozoa.
When the first treatment is completed the piping system must be flushed. Potassium permanganate will kill and convert most but not all organic matter in the system to carbon dioxide. It is likely that dead protozoa will break loose from the pipe walls and flow along with the water. First remove any material from the wet well and filters. If possible flush the system to a pond, if not, remove sprinklers at the far ends and allow water to flow until there is no particulate matter in the system. Check filters on individual sprinkler heads to insure all matter is removed.
One treatment will be effective in removing the bulk of the issue, however, a retreatment in 2 weeks is recommended to insure the system is truly clean.
Algae will always be in water systems, the maintenance objective is to periodically kill the algae before it can create a problem. During the warmer time of the year monthly maintenance applications may be needed. During colder seasons treatment every two or three months should be able to keep the system clear. The application methods and amounts will remain the same, however, flushing may not be necessary.
Clean Up and Spills:
It is important to have a solution nearby to neutralized the potassium permanganate in case of spills. Spills are easy to spot due to the purple color, when fully neutralized the spill will be clear. Potassium permanganate can be neutralized with a 3% hydrogen peroxide solution, 2 tbsp per 100 gallons (1 cup per 500 gal) using a 34% initial hydrogen peroxide solution. Mix the neutralizing solution in a hand held spray bottle or small garden chemical application sprayer.
Golfdom, Chip Howard, Ph.D.| June 2, 2016