How to Control Algae in Hydroponics
The hydroponic system, although has plenty of benefits over conventional soil culture, faces some problems. Algae attack is one of most common concerns in hydroponics. You can identify it easily from the typical green, black, brown or black texture it has; growing mostly on the nutrient media, in nutrient channels and pumps, and blocking the drippers. They also emit an earthy odor when substantial accumulation and decomposition take place inside the culture media.
Algae infestation is an outcome of exposure of the nutrient solution and plants to light. The algae gradually uses up the nutrients and then dies and decomposes leaving the solution devoid of dissolved oxygen. It further spikes up the oxygen demand in the hydroponic medium. The roots of the plants do not receive oxygen. When the plant root system gets suffocated, it becomes vulnerable to pathogen attacks. Therefore, it becomes necessary to control algal growth in nutrient solutions. We have explained some simple ways to prevent infestation of algae in hydroponics.
The first thing that you must take care is, block all sources of light penetrating the hydroponic medium. Make the nutrient reservoir, channels, and entry and exit points of the solution absolutely light proof. You can do this by covering them with an opaque material. You can purchase algaecide products from the market and use them as recommended. A moderate amount of hydrogen peroxide is also capable of killing algae. However, make sure that young plants do not come in contact with hydrogen peroxide. Some of the natural methods that you can implement to control algae are: incorporating barley straw rafts in the reservoir and adding grapefruit seed extracts to the nutrient solutions.
It is always better to take every possible precaution to prevent growth of algae, instead investing on chemicals for eliminating them. If the growth is dense, then you have to clean the reservoir and refill it with fresh nutrient solution.