All About Algae
Algae are the oldest and most widely distributed form of plant life. They range in size from large ocean kelps to microscopic single cells, so small that a single drop of pond water may contain thousands of these simple plants.
Algae is an informal term for a large, diverse group of photosynthetic organisms that are not necessarily closely related, making them polyphyletic.
Microscopic algae in large quantities form the familiar layer on ponds and ditches. Most other forms of algae are found in streams, on rocks, and in moist environments.
Algae such as microscopic oscillatory species live in and on the soil.
Some algae live in association with other organisms:
- Lichens consist of algae living in union with fungi
- Algae can even live on the back of a snail
The five major groups of algae are:
- Blue algae
- Green algae
- Diatoms
- Red algae
- Brown algae
Algae are not closely related in an evolutionary sense, and the phylogeny of the group remains to be delineated.
Specific groups of algae share features with protozoa and fungi that, without the presence of chloroplasts and photosynthesis as defining features, make them difficult to distinguish from those organisms.
In some cases, algae appear to have a closer evolutionary relationship with protozoa or fungi than with other algae.
Growing and Dealing with Algae
Finding algae on or around your plants—usually on the top of your growing medium—is not the end of the world.
Having algae present is not immediately harmful to plants. However, if left uncontrolled under the right conditions, it can negatively affect plant health.
Common Issues with Algae
- Competes for moisture and nutrients
- Creates an overly damp growing environment
- Can contribute to poor root zone conditions
Solutions for Algae Control
Simple and effective ways to manage algae:
- Lower moisture levels around affected areas
- Reduce or remove light exposure to algae growth zones
- Reset your growing medium
How to Reset Your Medium
To reset your medium:
- Flush with a Hydrogen Peroxide solution
- Mix: 1ml Hydrogen Peroxide per 10L of water
- Flood the medium thoroughly
- Follow with a low-strength A/B base nutrient solution
- Allow plants to recover after sterilisation
