The Paradox
Mbuna evolved in Lake Malawi where massive schools swirl around rocks. Crowding is natural for them.
In a sparse tank, a dominant male fixates on the few subordinates and kills them. In a crowded tank, no single fish gets all the aggression.
Stocking Formula
Rule: 1 fish per 15L water in filtered tanks with strong biological capacity. A 400L tank can hold 25-30 adult mbuna.
Aim for male:female ratio of 1:3 minimum. More females means more breeding sites to dilute aggression.
Filter Power Required
Overstocked tank needs overstocked filtration. Target 8-10x tank volume per hour total turnover.
Dual canisters, sumps, or canister + HOB combos work. Weekly 40-50% water changes are mandatory.
When Overstocking Fails
Overstock only works with compatible mbuna groups. Mixing delicate species (aulonocara) with aggressive mbuna crashes.
Also fails in new setups. Wait 6 weeks post-cycle before adding full stock.