Aquarium Algae FAQ: Types Causes and Removal
Algae is the single most-asked problem at any aquarium counter, and the wrong-type-of-algae diagnosis is what wastes most keepers’ time and money. The aquarium algae faq below pairs each major algae type with its true cause and a one-shot Singapore-specific fix. This aquarium algae faq reflects daily diagnostic conversations at Gensou Aquascaping in 5 Everton Park, where staff identify algae from phone photos before recommending products. Each question stands alone; this guide answers the eleven questions Singapore aquarists ask most about algae.
What Are the Main Types of Aquarium Algae?
The six common types you will meet are black beard algae (BBA), green spot algae (GSA), green dust algae (GDA), blue-green algae (BGA, actually cyanobacteria), hair or thread algae, and brown diatoms. Each has a different cause and a different fix. Misidentifying type leads to throwing money at the wrong solution. Take a clear photo first, confirm type, then act.
What Causes Black Beard Algae and How Do I Remove It?
BBA — fuzzy black or dark green tufts on hardscape and slow-growing plants — is driven by fluctuating CO2 and high organic load. Stabilise CO2 with a check valve and ensure the bubble rate is constant 24 hours of the photoperiod. Spot-treat with liquid carbon dosed directly onto the affected area using a syringe. Amano shrimp and SAE eat it once it dies and turns red.
What Causes Green Spot Algae?
GSA — small hard green dots on glass and slow-leaved plants — is a phosphate deficiency signal. Counterintuitively, dosing more phosphate via a complete fert like APT solves it. Many Singapore tanks running RO water with no PO4 supplementation get GSA within a month. Scrape with a magnetic glass cleaner from the aquascaping tools range and dose phosphate.
What Causes Green Dust Algae?
GDA — fine green powder coating glass and décor — is usually a young-tank phenomenon driven by inconsistent light schedules and unstable nutrient ratios. The proven fix is a full blackout for four days, then siphon off the dead algae during a large water change. Set lights on a timer running consistent eight-hour photoperiods after the blackout.
How Do I Beat Blue-Green Algae?
BGA is cyanobacteria, not true algae, and forms slimy dark green sheets across substrate and slow plants. It thrives in low-flow areas with high organics. Increase circulation, vacuum the affected substrate, and dose erythromycin (often labelled as Maracyn) for four days. A complete blackout works alone in many cases. The musty smell from BGA is unmistakable.
How Do I Get Rid of Hair Algae?
Hair algae — long green strands clinging to plant edges — comes from excess light and unbalanced macros. Reduce photoperiod to six hours, manually remove with a toothbrush twisted into the strands, and add Amano shrimp at one per ten litres. Caridina multidentata is the most aggressive eater. Spot-dose liquid carbon for stubborn patches. Recovery takes three to four weeks.
What Are Brown Diatoms?
Brown diatoms — soft brown dust coating glass and substrate — are nearly inevitable in new tanks during the first 6-8 weeks. They feed on silicates released by fresh substrate and do no harm. Otocinclus catfish and nerite snails graze them. Diatoms vanish on their own once silicates deplete; resist the urge to throw chemicals at them.
Will Reducing Light Fix Algae?
Sometimes. Excess light drives hair algae and GDA but does little for BBA, GSA or BGA, which depend more on CO2 and nutrients. The first move is consistent timing — wild swings in photoperiod feed every algae type. Run a timer at the same hours daily before reducing total intensity.
Will Algae Eaters Solve the Problem?
Algae eaters reduce visible algae but never fix the underlying imbalance. Amano shrimp, otocinclus, nerite snails and SAE are the proven workhorses. Avoid plecos in planted tanks — they outgrow nano setups and shred soft plants. The water care range handles parameter side; biological cleanup follows.
How Do I Prevent Algae Long-Term?
Stable CO2, consistent photoperiod under nine hours, weekly water changes of 30-40 per cent, modest stocking, and a balanced fertiliser routine. Most algae outbreaks trace back to one of these five fundamentals being off. Fix the root cause and visible cleanup follows in weeks.
Should I Use Algaecides?
Treat algaecides as last resort. They work short term but rarely fix root cause, and many crash plants alongside the algae. Liquid carbon (glutaraldehyde) is the most plant-safe option for spot-dosing BBA. Avoid copper-based algaecides in shrimp tanks entirely — copper levels lethal to shrimp persist long after dosing ends.
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Still Have Questions About Your Tank?
Drop by Gensou Aquascaping — most walk-in questions get answered in under 10 minutes by someone who has set up hundreds of tanks.
5 Everton Park #01-34B, Singapore 080005 · Open daily 11am – 8pm
