Demasoni cichlid care guide
Also called: Demasoni, Pseudotropheus demasoni
The demasoni is a small but very aggressive mbuna from Lake Malawi, striped bold blue and black. It reaches only about 3 in (8 cm), yet it needs a group of 12 or more in a 4 ft (120 cm), 55-gallon (208 L) rock tank to spread out its aggression.
Demasoni cichlids need a tank of at least 55 gallons (208 L), a group of 12 or more, and water at 24–27°C (75–81°F) with a pH of 7.5–8.5. They grow to about 8 cm (3.1 in) and are aggressive.
Plan a tank with demasoni cichlidsSee all tank mates
Demasoni cichlid quick facts
| Scientific name | Chindongo demasoni |
|---|---|
| Family | Cichlidae |
| Origin | Pombo Rocks, Tanzanian shore of Lake Malawi, East Africa (Vulnerable in the wild; aquarium fish are captive-bred) |
| Adult size | 8 cm (3.1 in) |
| Minimum tank | 55 gallons (208 L), at least 120 cm (47 in) long |
| Temperature | 24–27°C (75–81°F) |
| pH | 7.5–8.5 |
| Hardness (GH) | 10–20 dGH |
| Group size | 12 or more, with more females than males (group) |
| Temperament | Aggressive; males fight each other |
| Swims at | Middle |
| Diet | Herbivore (mostly plants and algae) |
| Care level | Hard |
| Lifespan | 5–10 years |
| Safe with shrimp? | No, eats shrimp |
| Safe with plants? | No, eats or uproots plants |
- Known jumper: keep a tight-fitting lid.
Tank setup
A group of a dozen or more needs at least a 55-gallon (208 L) tank 4 ft (120 cm) long. Fill it with rock piles full of caves so weaker fish can get out of sight. Leave some open sand, set rocks directly on the glass, and keep a tight lid on.
How many demasoni cichlids in a tank?
The smallest common tank that suits demasoni cichlids is a 55 gallon. Here is roughly how many fit in each size when they are the only fish, based on adult size and waste output. Leave room if you want tank mates.
| Tank | Demasoni cichlids (alone) |
|---|---|
| 3 gallon | Too small |
| 5 gallon | Too small |
| 10 gallon | Too small |
| 15 gallon | Too small |
| 20 gallon | Too small |
| 20 gallon long | Too small |
| 29 gallon | Too small |
| 40 gallon | Too small |
| 55 gallon | 12–17 |
| 75 gallon | 12–24 |
| 125 gallon | 12–40 |
Numbers are bioload limits only. Males fight, so keep a group of 12 or more with more females than males.
What you need for demasoni cichlids
Sized for a 55 gallon tank, the smallest common size that suits a group of 12 demasoni cichlids. For a different tank or a mix of fish, use the stocking calculator for a list sized to your plan.
Tank and equipment
- 55 gallon aquarium (tank or kit) (opens Amazon in a new tab)Bigger tanks are more stable and easier for beginners. How to choose
- Aquarium stand for 55 gallons (opens Amazon in a new tab)The water alone weighs about 459 lb (208 kg), before glass, gravel and rock. How to choose
- 2 adjustable heaters, 100 W each (opens Amazon in a new tab)Holds about 78 °F (25.5 °C) in a room at 65 °F (18 °C). Two heaters keep the tank warm if one fails. How to choose
- Aquarium thermometer (opens Amazon in a new tab)Check it daily: heaters can fail stuck on or off. How to choose
- Canister filter rated 330–550 GPH (opens Amazon in a new tab)Heavily stocked or messy fish: 6–10 times the tank volume per hour. How to choose
- About 50 lb of aragonite sand (opens Amazon in a new tab)Enough for a layer about 1.5 in (4 cm) deep. Aragonite helps keep the water hard and alkaline for rift lake cichlids. How to choose
- Water conditioner (dechlorinator) (opens Amazon in a new tab)Removes chlorine and chloramine from tap water. Seachem Prime is a popular, concentrated choice. How to choose
- Liquid test kit (ammonia, nitrite, nitrate, pH) (opens Amazon in a new tab)Liquid kits are more accurate than strips. The API Freshwater Master Test Kit is the common choice. How to choose
- Gravel vacuum (siphon) (opens Amazon in a new tab)Cleans the gravel and does the water change in one go. How to choose
- LED aquarium light, about 48 in long (opens Amazon in a new tab)Match the light to the tank length. Basic LEDs grow easy plants. How to choose
Food and extras for demasoni cichlids
- Rocks for caves (holey or lace rock) (opens Amazon in a new tab)Rift lake cichlids need piles of rock to claim territories and break lines of sight.
- Spirulina cichlid pellets (opens Amazon in a new tab)Plant-rich food for algae-grazing Malawi cichlids. Avoid high-protein foods for them.
- Caves and hides (opens Amazon in a new tab)Gives shy and territorial fish their own space.
- Tight-fitting lid for a 55 gallon tank (opens Amazon in a new tab)Demasoni cichlid can jump out of an open tank.
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Water parameters
Keep it at 24–27°C (75–81°F), pH 7.5–8.5 and hard water (10–20 dGH). Buffer with crushed coral or aragonite. Use strong filtration and change 30–50% of the water every week.
Best tank mates for demasoni cichlids
These popular species share demasoni cichlids' water needs and temperament. See the full list of 1 good matches.
Avoid keeping demasoni cichlids with
- Angelfish: Demasoni cichlid is a Lake Malawi cichlid. It needs a Lake Malawi tank: hard, alkaline water (pH 7.5–8.5), plenty of rockwork and other cichlids from the same lake. Angelfish don't belong in that setup.
- Betta fish: Demasoni cichlid is a Lake Malawi cichlid. It needs a Lake Malawi tank: hard, alkaline water (pH 7.5–8.5), plenty of rockwork and other cichlids from the same lake. Bettas don't belong in that setup.
- Bristlenose pleco: Demasoni cichlid is aggressive and will bully or injure peaceful bristlenose plecos.
- Bronze corydoras: Demasoni cichlid is aggressive and will bully or injure peaceful bronze corydoras.
- Cherry shrimp: Demasoni cichlid eats small shrimp like cherry shrimp.
- Common goldfish: They need different temperatures: Demasoni cichlid 24–27°C (75–81°F), common goldfish 15–22°C (59–72°F).
Feeding
Mostly herbivorous. Feed a spirulina flake or small mbuna pellet as the base, plus blanched spinach, nori or romaine lettuce. Give mysis or other meaty foods only now and then, and never beef heart, as rich food can cause bloat.
Behavior
One of the most aggressive mbuna for its size. It attacks its own kind and any fish with a similar blue-barred pattern, and it will take on fish several times larger. Keep a big group with several females per male, alongside robust mbuna of other colors such as yellow labs. Never mix it with peacocks or other gentle haps.
Breeding
A maternal mouthbrooder. Males and females look alike, so start with a large group of juveniles and let them sort out. The female broods for about three weeks without eating. Fry fight from an early age and need space or separating as they grow.
Tips from experienced keepers
- Keep a group of 12 or more. Groups of 3–6 often end with one fish bullying the rest to death.
- Avoid other blue-and-black barred mbuna, which demasoni treat as rivals.
- Add demasoni last to an established mbuna tank, as they target newcomers.
- Males and females look the same. Buy a large group of juveniles rather than trying to sex them.
- Keep a spare tank ready in case one fish gets singled out.
Frequently asked questions
How many demasoni should be kept together?
Most experienced keepers recommend at least 12. In a big group the aggression spreads out, while in a small group a dominant male often harasses the others until they die.
Are demasoni cichlids aggressive?
Yes. They are among the most aggressive mbuna for their size, especially toward their own kind and other blue-striped fish.
Can demasoni live with yellow labs?
Usually yes, and it's a classic pairing. The yellow color and different pattern mean demasoni rarely see labs as rivals, but the tank still needs lots of rockwork.
Sources
We checked these references when writing this page. Values are for healthy long-term keeping, not survival limits. Last reviewed 2026-10-13. See our editorial policy.