African Cichlids: Aggression, Stocking and Water
Aggression Comes With Them
The UK's Ornamental Aquatic Trade Association (OATA) describes Malawi cichlids as colorful, diverse and aggressive, but otherwise undemanding and easy to keep. Most sold are captive-bred.
Aggression centers on rock territories, feeding and breeding, rather than appearing at random, so a keeper who learns the patterns can usually see trouble coming. Many classic community fish would be bullied or killed in a cichlid tank, so most keepers run cichlid-only tanks.
Stocking: Why Crowding Is Used
OATA advises keeping Malawi cichlids in groups of at least 15, slightly overcrowded, with more females than males of each species, because small groups often fight. Spreading aggression across many fish stops it focusing on one or two.
That only works with filtration well beyond normal, weekly water testing and a keeper who notices early chasing and steps in. Build up numbers slowly so the filter bacteria can keep pace, and ask your aquatics store to check your plan against your tank size.
Hard, Alkaline Water
Lake Malawi's water is hard and alkaline, very different from the soft water many community fish come from. OATA gives 73–81°F (23–27°C), pH 8.0–8.6 and hard water as a general guide. A coral sand substrate helps buffer the water, and a heater keeps the temperature steady all year.
Lake Tanganyika cichlids also like hard, alkaline water but differ in size and behavior, so check each species before mixing. These figures are typical; check with a specialist keeper or a good aquatics store.
Gear for a Cichlid Tank
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Buy before the fish: an oversized filter (a canister suits big tanks), an air pump for extra oxygen, coral sand to buffer the water, and plenty of aquarium-safe rock for caves. A cichlid pellet suits their busy metabolism, and a reliable test kit tracks the water weekly.
Rockwork and Filtration
Stacked rock with plenty of caves gives each fish a spot to claim and breaks up lines of sight, so a chased fish can get out of view. A bare tank concentrates aggression. Rearranging the rocks can reset territories when one fish starts bullying. Make stacks stable, resting on the glass rather than on sand, because cichlids dig.
Cichlids are messy eaters, and a crowded tank makes a lot of waste, so an oversized filter is standard practice, not an upgrade. Digging also uproots most plants; only tough plants attached to rock or wood tend to survive. See filters and pumps.
Frequently Asked Questions
The questions that separate browsers from cichlid keepers.
Are African cichlids too aggressive for most keepers?
No, but peaceful-community stocking rules don't work for them. Success comes from planning for their territorial nature from the start.
Why do people overstock cichlid tanks?
A large, slightly crowded group spreads aggression across many fish. OATA suggests groups of at least 15 for Malawi cichlids. It needs strong filtration and close watching, so build up slowly.
Do they need different water from a community tank?
Yes. Malawi cichlids want hard, alkaline water, around pH 8.0–8.6. Coral sand helps keep it there; test weekly.
Can African cichlids live with other fish?
Rarely with typical community fish, which get bullied. Even different cichlid species need matching size and temperament.
How big a tank do they need?
OATA recommends at least about 53 gallons (200 liters) for a reasonable community, and bigger is more stable.
When has aggression gone too far?
A fish that hides constantly, has torn fins that don't heal or can't get to food needs help. Rearrange the rockwork, move the bully, or ask trained aquatics staff or a vet who treats fish.
Related Reading
- Filters and pumps: sizing up for a messy tank.
- Water care and testing: weekly checks.
- Community tropical tanks: the peaceful alternative.
A fish that hides and stops eating could be bullied or unwell. Test the water first, then ask trained aquatics staff or a vet who treats fish.