African Cichlids: Size, Stocking, Substrate and Tank Mates

African cichlids are colourful, territorial freshwater fish, most of them from Africa's Great Lakes, Malawi, Tanganyika and Victoria. Wikipedia counts at least 1,760 described cichlid species worldwide, about 1,600 in Africa, and explains that the lake species evolved unusually fast: the Lake Victoria cichlids arose within the last 10,000 to 15,000 years.

In the aquarium trade the Lake Malawi fish dominate, in three groups:

• Mbuna, a Tonga word meaning rockfish: rock-dwelling, algae-grazing and the most aggressive (Wikipedia)
• Peacocks, Aulonocara: males are brightly coloured, and Aquarium Science keeps peacock tanks males only
• Haps: larger fish, many of them predators, which Aquarium Science stocks lightly

The difference matters because That Pet Place advises against mixing mbuna with peacocks, since mbuna are more aggressive.

Most aquarium African cichlids end up 4 to 6 inches long. Practical Fishkeeping gives mbuna as 7.5 to 10 cm (3 to 4 in) in the wild but 12.5 to 15 cm (5 to 6 in) in well-fed aquariums, and That Pet Place says most peacocks grow 4 to 6 inches and most mbuna 5 to 6 inches.

The family as a whole ranges far wider. Wikipedia gives the smallest cichlid, the female Neolamprologus multifasciatus shell-dweller from Lake Tanganyika, at 2.5 cm (1 in), while some species approach 1 m. Juveniles sold at 2 inches or less still show juvenile colours and are hard to sex, as LiveAquaria notes, so buy with the adult size in mind.

For mbuna, more fish in a bigger tank, not fewer. Practical Fishkeeping calls 20 individuals an absolute minimum, with 30 or 40 better, in a tank of at least 120 cm (4 ft), ideally 120 by 60 by 60 cm, and 180 litres (40 gallons) at the very least, 240 litres (53 gallons) or more preferred. It also advises at least two females for every male of each species.

The reason is how aggression spreads. Wikipedia notes that overcrowding helps reduce aggression in mbuna, because a dominant male cannot single out one victim. Aquarium Science's author, writing from his own tanks, stocks mbuna at about one 4 to 6 inch fish per 2 gallons, gives '37 in a 75-gallon' as an example, and keeps peacock tanks males only. Heavy stocking only works with strong filtration: Practical Fishkeeping asks for zero ammonia and nitrite and nitrate below 40 ppm.

Yes, most are aggressive, and the usual advice is to keep them with other African cichlids of similar size and temperament. Wikipedia describes mbuna as very aggressive and territorial and not suitable for beginners. That Pet Place calls Malawi and Victoria cichlids generally not community-safe, and Practical Fishkeeping advises against mixing them with other kinds of fish.

Not every source agrees. The author of Aquarium Science reports keeping Malawi cichlids successfully with Tanganyikans, Victorians, jewel cichlids, giant danios and tiger barbs. Treat that as one experienced keeper's result, not a default.

One rule every source supports: keep enough females of each species. Practical Fishkeeping warns that a female without males of her own species may cross with another species, which produces hybrids.

Either works if it is not sharp. That Pet Place says the substrate can be whitish coral sand of the kind used in marine tanks, black freshwater sand or ordinary decorative gravel, as long as it has no sharp edges. What matters more is what the substrate and rocks do to the water:

• Lime-based rock and substrate keep the water hard and alkaline; That Pet Place recommends calcareous decor or filter media for this, and Practical Fishkeeping suggests piles of lime-based rocks about 15 cm across
• Plenty of rockwork gives females, fry and weaker males somewhere to hide and breaks lines of sight (Practical Fishkeeping)
• No driftwood: That Pet Place notes wood lowers pH

Target water from That Pet Place is pH 7.8 to 8.5, 8 to 12 dKH and 75 to 82 F; Practical Fishkeeping gives pH above 7.5 and 24 to 26 C.

Mbuna graze algae in the wild, and overfeeding rich food is linked to a serious disease. Practical Fishkeeping recommends algae-based, herbivorous food for mbuna, avoiding rich carnivorous food, and a day without food each week. It describes Malawi bloat as a swollen neck and belly with bulging eyes that is usually fatal. That Pet Place also warns that excessive protein can cause hole-in-the-head disease and Malawi bloat.

A fish showing these signs needs prompt advice from an aquatic vet or an experienced fish shop.

Retail prices on one day at two specialist sellers:

• LiveAquaria: dragon blood peacock from $11.99, electric blue from $24.99, demasoni $24.99 (rated Semi-Aggressive), frontosa (captive-bred) from $29.99, yellow peacock $44.99, red peacock from $49.99; the collection ranged from $11.99 to $238.99
• Ron's Cichlids (fish farm-raised in the US for over 30 years): assorted hybrid peacock males $19 to $35, white tail acei $19, Buccochromis lepturus green $125

Size and sex change the price a lot, so compare like with like.

Lake Victoria shows how fragile these fish are in the wild. After Nile perch and other pressures arrived, cichlids fell from about 80% of the lake's fish catch to only 1% by around 1980, and roughly 40% of its haplochromine species, more than 200 of over 500, are believed extinct (Wikipedia). It is one more reason never to release aquarium fish into any lake, river or pond.