Aquascape To start with, the real Lake Malawi has rocky shores and a sandy (muddy) bottom while vegetation is not very common. On the other hand most of the Malawi fish that we keep in our tanks are raised in captivity therefore one should take care of factors that will affect the fish due to the genetic information they carry, but he doesn’t have to be very strict when it comes to tank decoration. Mbuna will graze the algae (mainly for crustaceans) from the rocks in the aquarium, will dig to spawn and will run to hide under a rock for shelter. Non-mbuna will do the same with the exception of algae eating. Therefore the aquascape should contain as many rocks as possible (creating hiding places) and a sandy bottom. Alternatively, one can use crushed coral (also buffers the water and increases the hardness) or fine grain gravel.
The rocks should not have any sharp edges which could scratch the fishes. If you collect them yourself it is better to get rocks rounded by the water movement. Plants can be added for the aesthetic pleasure of it but they also provide shelter to many young mbunas AND they remove nitrates. Therefore they can serve many roles in your tank even if they are not part of the natural habitat of these cichlids. When I sent a photo of my mbuna tank to my Italian friend Francesco Zezza (also in love with Africans), he replied that “there are probably more plants in your tank than the ones I saw during diving in the Lake Malawi”. I know that he is right. However, I think it is more pleasing, it shows the yellows and reds of these cichlids much more vividly and they create a working biotope.
Most mbunas may attack plants to eat the soft leaves, while all species may uproot them in the process of digging. Plants should be secured in place by adding rocks around their base. Use hard plants such as Vallisneria, Cryptocoryne or Anubia species. You can use some fast growers during the initial stages of your tank which may protect it from algae bloom. Such species include Egeria densa, Hygrophila corymbosa etc. Unless you have a really big tank (more then 150 cm in length) do not choose the Vallisneria gigantea species which, as the name implies, grows to more than 2 meters and is a really fast grower. Rocks should be secured in place too, otherwise the rock pile may fall apart due to digging and break the side glass of the tank bottom. You can either glue rocks together using aquarium silicone or put styrofoam on the base of the tank and then put the rocks on it. Always place the rocks first and then the sand. Styrofoam should be covered with rocks before the addition of water in the tank otherwise it will float.
Bear in mind that your Malawis will change the decoration to fit their own needs. It is a battle you can’t win. They will keep on moving the gravel where they want it to be or uproot a specific plant every time you put it back. Cichlids are very sensitive to their environment mainly because they use it to establish territories. Any plant or rock is a boundary and is treated like that. When doing your water changes take some time to count your fish and to see what is happening on the back side of your tank. You will be surprised to see what these beauties can do in just one week. It took me three weeks to find the sceleton of my second male Melanochromis auratus which I thought was hiding. The dominant male had killed it and left the carcass under a rock. Recently, I was shocked to see that a 25 Kg rock was actually standing in the air since almost all gravel had been removed under it. A remarkable work that took the fish more than a month to accomplish. Adding 5 more kilos of gravel on that spot temporarily solved the problem. Needless to say the suspect is identified (Melanochromis chipokae) and is working on it again.
Space (tank size) When it comes to housing African cichlids the bigger is always the better. Many hobbyists keeping Africans have tanks well exceeding the 1.000 liter mark and even 2.000 liters is not very rare. Buying a small tank of 20-30 liters is not suitable for cichlids from Lake Malawi except for the smallest species. This is mainly the reason these species are not for the beginner. One is supposed to learn the basics of fish keeping with a small community tank and then move to a bigger tank with more demanding fishes. In my experience, the smallest tank that will allow you to have a descent number of Lake Malawi cichlids and observe their unique behavior and breeding habits is a 350 liter (90 gallon) tank. I have personally witnessed the change in behavior of many species when I removed them from their 500 liter tank to their final home (1300 Liters). Many peaceful and inactive species in the smaller tank were proved to be very active and aggressive. Species that didn’t spawn did that on the spot. It was amazing to see species kept for a year in the first tank to spawn within one week, despite the different environment; instant acclimatization and use of the extra space.
My plan is to keep the big tank as empty as possible though the temptation is always there… I have just 21 fishes in it and I do not intent to have more than 35. When choosing (or building) your tank it is always better to go for a tank which is shorter but with more depth. When aquascaping with rocks, ten more centimeters can make the hell of a difference. I would recommend 50 cm as the least depth that will allow you to build a good and working aquascape. With this sort and size of tanks, special care should be taken to ensure that your floor can take the weight. A 350 liter tank filled with water, gravel and rocks can weight much more than 600 Kg. If we assume its dimensions to be 150 cm long X 50 cm deep (0,750 sq. meters) then we already have a load of 800 Kg / square meter which is more than most floors will take (bearing walls may take a bit more). Setting this sort of tank on special supports (metal or concrete) that spread the weight evenly is a must. Always use some sort of foam plastic between tank and support. Moreover, you should put this tank on a solid floor (marble or stone) and not wood.