Plants often die not from internal deficiencies, but because they are physically strangled and smothered by epiphytic algae. Aggressive algae like BBA (Black Beard Algae), GSA (Green Spot), and staghorn grip tightly to the leaf epidermis. When algae cover exceeds 50-60% of the leaf surface, the plant is physically unable to photosynthesize: light is shielded by the algae layer, and O2 and CO2 gas exchanges are blocked. This leads to the necrotic death of the individual leaf.

Yellowing, rotting, and death occurring exclusively and locally under algae-covered areas. Old or slow-growing leaves (e.g., Anubias) have black, spongy, or green-encrusted edges that spread until the whole leaf rots. The plant stops producing new leaves because it expends all its energy trying to keep the diseased leaves alive.

Extremely slow plant growth due to a lack of CO2 or nutrients, making it an easy target. Poor water flow allowing organic debris to settle on the leaves, becoming a substrate for algal spores. General tank imbalance (ammonia, excessive lighting).

Mechanical removal of the obstruction is necessary. Drastically cut off at the base all leaves that are more than 50% affected (they will never recover). On healthy but spotted leaves, perform a local spot-treatment with a syringe (filter off) using liquid carbon (Glutaraldehyde, e.g., Excel) or Hydrogen Peroxide (3%).

Ensure vigorous and rapid plant growth by balancing Light, CO2, and Fertilizers. Highly healthy plants produce antimicrobial enzymes and constantly shed their thin waxy surface layer, physically preventing algal spores from anchoring.