Quick answer
New reefs often pass through diatoms, films, algae and changing microbial communities while nutrients and surfaces stabilise. Identify the growth, keep chemistry steady and correct causes gradually.
What to check first
- Confirm ammonia and nitrite remain controlled
- Test nitrate, phosphate, salinity and alkalinity trends
- Check light duration and intensity
- Identify whether the growth is diatoms, cyanobacteria or dinoflagellates
Write down the test results, recent maintenance, new livestock, feeding changes and equipment faults. A short timeline prevents repeated guesses and makes patterns easier to see.
A practical action plan
- 1. Remove excess growth manuallyRecord what changes and retest before making another major adjustment.
- 2. Maintain flow and exportRecord what changes and retest before making another major adjustment.
- 3. Avoid adding too many grazers at onceRecord what changes and retest before making another major adjustment.
- 4. Change one variable at a timeRecord what changes and retest before making another major adjustment.
What to avoid
Do not sterilise the system or chase zero nutrients.
When it is urgent
Livestock distress, toxic dinoflagellate signs or oxygen depletion requires immediate action.
How to prevent it next time
Use stable routines: quarantine additions, test before and after major changes, maintain backup aeration, keep equipment accessible, and record enough detail to compare today with the aquarium’s normal baseline. Prevention is usually cheaper and safer than emergency correction.
Research and review
This is original AquaNexus writing prepared for practical aquarium use. The husbandry framework was checked against authoritative veterinary, safety, scientific or specialist references.
Test rather than guess and make changes at a pace the livestock can tolerate. This guide does not replace aquatic veterinary advice. Follow product labels and local electrical-safety requirements.