How do I prevent algae growth?
Written by
Kiana Okafor
Reviewed by
Prof. Charles Hartman, Ph.D.Self-watering containers can be prone to algae growth if light is penetrating the reservoirs, which will grow as a green slimy mass that can clog the wicks and compete with plants for necessary nutrients. Eliminate algae through intentional design elements and regular maintenance. By taking actions to prevent algae from appearing, there is less wasted time and the self-watering systems are more likely to work efficiently all year round.
Light Blocking Techniques
- Use opaque materials like painted ceramic or metal
- Wrap clear reservoirs with aluminum foil
- Install UV-resistant liner layers
- Add floating shade balls to water surface
Water Treatment Methods
- Add 1 tsp (5 ml) hydrogen peroxide per gallon monthly
- Use cinnamon sticks as natural antifungal agents
- Replace 25% water weekly with fresh supply
- Install charcoal filters in reservoir inflow
The design of the reservoir significantly influences the amount of algae that grows in the reservoir. A client in Florida was able to reduce outbreaks of algae by 80% by using light-blocking foam inserts. They used 4-inch (10 cm) thick foam cut precisely for each opening beneath the soil beds to create complete darkness in the water chambers below.
Going through monthly maintenance will help prevent algae colonies from taking hold. You should scrub the underside of the reservoir walls with a stiff brush and a vinegar solution. If algae are entrenched, food-grade citric acid is an alternative to vinegar. Use 2 tablespoons per gallon of water to dissolve mineral deposits where spores may be harboring. Rinse the reservoir thoroughly after scrubbing with vinegar or citric acid solution.
Water quality issues exist in humid environments. Don't put organic fertilizers where they will feed algae, put them into the soil in slow-release pellets instead. A Houston gardener switched from regular vegetation feeds to synthetic nutrients, and after midnight, all the blooms disappeared when she put in simple charcoal filter cartridges.
Future containers may incorporate UV sterilization lights. UV sterilization lights are powered by solar energy and are built to zap algae at night without the use of chemical solutions. This kind of technology may prevent algae while ensuring self-watering containers are still hand-off experiences for busy plant lovers.
Read the full article: Ultimate Guide to Self Watering Containers
