HLLE (Head and Lateral Line Erosion)
A chronic condition causing pitting, erosion, and discoloration along the head and lateral line. Common in tangs and angelfish. Linked to nutritional deficiencies (vitamin C, D), activated carbon use, and poor water quality. Also called "hole in the head."
Check these symptoms in your tankSymptoms of HLLE (Head and Lateral Line Erosion)
- Pits or holes on head/lateral line
- Faded or lost color
- Lethargic / hiding more than usual
How to treat HLLE (Head and Lateral Line Erosion)
- Improve diet: add varied frozen foods, algae, nori, vitamin supplements
- Switch to carbon-free filtration or reduce carbon use
- Improve water quality: more frequent water changes, reduce nitrates
- Add vitamin C and D supplements to food
- Recovery is slow (months) but possible with consistent care
How to prevent it
- Feed a varied diet including Nori, Spirulina, Mysis, and enriched Brine shrimp
- Keep nitrates below 10 ppm for sensitive species
- Limit activated carbon use, replace regularly or use alternatives
Conditions with similar symptoms
Caused by a dinoflagellate parasite. Appears as a fine gold or rust dust on the fish. Highly contagious and fast-moving, often fatal if not treated immediately.
Bacterial (and sometimes fungal) infection affecting fins and tail. Usually secondary to stress or poor water quality. Fins appear to disintegrate from the edges.
Fluffy white or gray cotton-like patches on body, fins, or around mouth. Often secondary to wounds, fin rot, or poor water quality.
Not sure? Use the symptom checker
Many fish diseases look alike. Pick the symptoms you see in the free fish disease checker to compare likely causes, or scan a test strip to rule out a water problem first.