handbuch aquarienwasser
This section (final third) focuses on Algae (undesired algal growth) in aquaria: how algae enter tanks, why they proliferate (lack of fast-growing aquatic plants and excess resources), common triggers (new setups, lighting or maintenance changes, neglect), and specific algal groups (diatoms/kieselalgen, red algae, green algae, cyanobacteria). It gives identification challenges, ecology (light spectrum uses, pigments like fucoxanthin, phycoerythrin, phycocyanin), control strategies (mechanical removal, competition via fast-growing plants, appropriate lighting duration/intensity, CO2 ~20 mg/l, regular water changes—recommendation: ≥50% weekly, avoid chemical algicides), and treatment protocols (dark-treatment/dunkelkur steps including 70% pre-wash, aeration, stop CO2, 6–7 days darkness, partial exchange day 3–4, then two consecutive 90% water changes after re-illumination). It also reviews algae-eating fauna, the role of nutrient management and ‘‘algae-watering’’ versus ‘‘algae-starving’’ misconceptions, and literature/resources. Practical tips: add Ceratophyllum demersum early to combat diatoms; waterlenses (Lemna sp.) as phosphate sinks; UV-C for planktonic algae; caution about chemical treatments and decomposition risks.
Questions this document answers
About 2 mg/l H2O2.
0.02 mg/l NH3 (chronic exposure threshold).
From about 0.05 mg/l Cl2 damage can occur.
Up to 50 mg/l NO3.
Approximately 0.005–0.02 mg/l PO4 (plants often need at least 0.02 mg/l).