Algae grows rampant when there is sufficient light and nutrients available in the water Here a young Water Lilly is being choked by an algae bloom in a man made pond. Imagine what would happen if the pond was filled with nutrient solution! - Since we can't take the nutrients out of a hydroponic system, keep stray light from reaching the nutrient solution at all times.
Fresh outbreaks of gray mold may be removed from plants with a dry, soft cloth. Be sure to remove all dead and dying plant matter from the garden as soon as you see it, because that is where Botrytis will flourish first.
"Damping off" is a problem caused by fungi that plagues seedlings and cuttings grown in unsterile, overly saturated media. It generally attacks the meristem just above the media, causing the plant to wilt and fall over. A wet-looking dark stem with a light powdery coating is the signature of damp off, as illustrated here. Use only sterile, fast draining growing mediums when starting seeds, and for additional protection, apply a light dusting of diatomaceous earth (horticultural DE) on and around the meristem.
While not a fungi per se, the infamous fungus gnat adores the same conditions and will wreak just as much havoc if left unchecked. Fungus gnats only become a problem where overly saturated growing media exists. While the adult gnat is nothing more than a nuisance, their larvae, which live beneath the surface, feast on young and tender roots. This situation can stunt growth, as well as open the door for disease and fungal outbreaks. When growing with a combination coir and perlite growing media in Dutch or Autopot systems, a top dressing of an inch or two of LECA stone will keep the surface dry and unappealing to gnats and most fungi because the LECA will help wick excess moisture up and away from the surface. Using a layer of LECA stone as a top dressing also helps keep the lightweight mediums in the pots when growing outdoors where they are unprotected from the wind and rain and reduces evaporative losses due to intense lighting..
Algae will grow just about anywhere there is stagnant water, excessive surface moisture, and light. It will grow inside reservoirs and within growing chambers that allow stray light to enter. Since algae is a type of plant, it will consume nutrients and continue to grow if left unchecked. In a reservoir, it poses little more than a slimy nuisance. But when it is allowed to grow unchecked on submerged roots, it will compete for food and oxygen. Algae will also grow on the surface of saturated growing media and should alert the grower to take corrective action when it appears. Scrape excessive algae to remove it, and then determine and correct the cause of the excess surface moisture. As a general rule of thumb, it is a good idea to flush your hydroponic system between crops with a 10% bleach solution to prevent the build up of fungi and algae over time.
Was this article helpful?