Algae and plant problems
Deficiency symptoms, the common algae groups, melting plants and invasive-species rules, with the evidence behind each claim.
Diagnosis in planted tanks is mostly pattern matching: which leaves are affected first, what the growth looks like, and what changed recently. These pages separate what plant physiology and the published sources establish from aquarium lore, and say so when the evidence is thin.
Algae pages describe each group by its biology first, then the control measures that growers and manufacturers actually publish.
10 guides
- Black beard algae: the red algae behind it and what sources adviseBlack beard (brush) algae are red algae despite their color. The likely genera, the alcohol test, conditions linked to it, and the control methods sources describe.
- Crypt melt: why new Cryptocoryne lose their leavesNew Cryptocoryne often drop their leaves within weeks of planting. What growers and the research on emersed and submerged leaves say, and how long regrowth takes.
- Cyanobacteria (blue-green algae) in a planted tank: causes and controlBlue-green slime is a bacterium, not an alga. What growers and the EPA say about it, the nitrate and phosphate link, and how blackouts and potassium spikes compare.
- Diatoms (brown algae) in a new planted tank: why they come and goThe brown film in a new tank is diatoms, algae with glass cell walls. Why they appear in the first weeks, what silica has to do with it, and what clears them.
- Green spot algae: what it is and what sources say causes itHard green spots on glass and slow leaves: the likely organism, the conditions growers associate with it, the phosphate disagreement, and how it is removed.
- Green water: why aquarium water turns green and how it clearsGreen water is a bloom of free-floating microscopic algae. What causes it, what Tropica and Aquasabi recommend, and how UV, blackouts and water changes compare.
- Hair, thread and fuzz algae: telling them apart and what helpsGreen filamentous algae in planted tanks: how thread, hair, fuzz and Cladophora differ, the light, nitrate and CO2 triggers growers name, and the grower remedies.
- Nutrient deficiency symptoms in aquarium plants: a symptom keyRead deficiency symptoms by where they start: old leaves for mobile nutrients, new growth for immobile ones. A symptom table with extension and grower sources.
- Emersed to submersed: why new aquarium plants change and drop leavesMost aquarium plants are grown out of water and must rebuild their leaves underwater. What the research on leaf form shows, and what to expect from pots and cups.
- Invasive aquarium plants and how to dispose of trimmings safelySeveral common aquarium plants are established in US waters and two are federal noxious weeds. What the official records say, and how to dispose of trimmings safely.