Green spot algae
Hard green dots on the glass and on slow-growing leaves.
Small, hard, round green spots on the front glass and on the leaves of slow plants such as anubias and java fern. They do not wipe off with a soft cloth.
- Main cause
- Strong light over slow-growing plants
- First fix
- Scrape the glass with a razor blade or algae scraper (plastic for acrylic tanks).
What causes it
- Strong light over slow-growing plants
- Low phosphate in planted tanks
How to remove it today
- Scrape the glass with a razor blade or algae scraper (plastic for acrylic tanks).
- Remove badly spotted leaves of slow plants.
How to stop it coming back
- Shade slow plants and shorten the light period.
- In a planted tank with fertilizers, check that phosphate is not near zero.
Fish and invertebrates that eat it
They keep it down once the cause is fixed; none of them clears a bloom on its own.