The Mbuna Aquarium (PART 1)

The Mbuna Aquarium

Introduction

Mbuna (um-boo-na) are a group of cichlids endemic to lake Malawi (mul-a-wee), one of the three rift lakes of Africa. They reside in the shallower areas where the algae rich rock reefs can be used as a source of both food and security. Their constant activity, brilliant color, and success with high stocking levels make mbuna a popular choice for a cichlid aquarium. Not only is their beauty and energy perfect for an exotic freshwater show tank, but their hardiness makes some of them as suitable for beginners as for more experienced hobbiests.

The biggest drawback to these fish is their aggression, although this does tend to make up most of their character and charm. It is imperitive that a suitable sized aquarium be provided in order to deal with some of this aggression. The aggression levels of the fish will only be amplified in the confines of an undersized tank, injuries and fatalities will be imminent. Mbuna vary in aggression from mildly aggressive to extremely hostile, most falling somewhere in between. When choosing species there is more then just color to consider, aggression levels are the largest factor in what species will work together, especially in aquariums of a more limiting size.

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Setting up the aquarium

The tank

The best advice in deciding on the size of the tank is as big as you can fit, or afford to go with. Any tank less then three feet in length is not a suitable environment for any mbuna. 29 gallons is NOT suitable. As far as cichlids are concerned this tank is the same as a 20 gallon, being only two feet long.

Length is the most important aspect when considering what type of tank to buy. A fifty-gallon tank that is four feet long is preferable to a fifty-gallon tank that is three feet long. Hex and cube tanks should be avoided completely, they are nearly useless for these fish because of an extreme lack of surface area. Mbuna are generally bottom dwellers, so aquarium height is the least important aspect--'tall’ tanks are undesirable.

Filtration

Mbuna are usually stocked in higher numbers in order to help distribute aggression, and you will want enough filtration to handle these levels. Canisters are great for bio-fitration because they hold a lot of media and are very versatile. Hanging power filters tend to have a higher flow which provides superior mechanical filtration. There is no reason why one can’t go with one of each. Having two filters also lets you stagger maintenance on them, ensuring that you always have a healthy bacterial colony. You can also go with two hanging filters, two canister filters, or another type of filtration altogether, as long as you are sure that have enough. It is always safer to go with too much then too little. In short - you can't have too much filtration with these fish.

The decoration

It is very important to provide many hiding spots for the less aggressive and sub-dominant fish, otherwise they can easily be cornered and beat upon, or end up living under constant stress that will eventually kill them through another illness. Providing many more hiding spots then there are fish and making them varied in size is ideal--including caves that may seem too small--it is amazing what these fish can squeeze into. I use solid rocks of various sizes and pile them up to create a natural network of caves and tunnels, and while some would deem my rockwork excessive I find the mbuna do very well with it. Any fish can quickly lose another one on it's tail, and larger surface area of rock allows for more room for grazing and less territorial battles. It is not necessary to use rocks, but hiding spots are a must and this is the most natural way to accomplish this.

The fish stores sell a variety of rocks, but charge much more then they should. You can get rocks from landscape suppliers for much cheaper, just look in the local yellow pages. You can even use rocks that you find locally. Regardless of where you obtain the rocks it’s safest to clean them as well as possible. Smaller rocks can be boiled or baked; larger ones can be rinsed with hot water or pressure-washed.

Many types of rocks can be used, and in the end what you choose is dependent on personal preference and what you can get your hands on. Some popular ones are granite, slate, holey rock, limestone, lava rock, lace rock, silica rock, and river rock.

When placing the rocks in the tank put them directly on the bottom glass. Mbuna are diggers, and if the rocks are rested on top of the substrate the fish will dig under the rocks and cause a collapse that can lead to injured or killed fish and even a shattered aquarium. Place the rocks in a formation that is sturdy and pleasing to the eye. You can use the sides and back of the aquarium to support the rocks, but try to make as many of them free standing as possible to reduce pressure on the glass. Play around with the rocks until you are comfortable that you have a sturdy structure. Keep in mind that it can take some experimenting to create a rock reef that is both aesthetically pleasing and a good environment for the fish. Stacking the rocks higher will encourage the fish to use more height of the aquarium, but always leave at aleast a few inches at the top to maximize grazing area.

Some hardy plants such as Java Fern and Annubias can be kept with these fish, but you may find that they get dug up and end up floating. Likewise fake plants will work in a similar way. Avoid using driftwood in an mbuna tank, as it can bring down the PH of the water, but a little bit will not make a noticable difference. Some rocks like limestone and holey rock will actually help to buffer the water, and are excellent for African rift lake tanks for this reason.

A Word on Algae

Common aquarium algae actually provides little nutritional benefit to the fish, but it does keep them busy grazing - something they spend a large amount of time doing in the wild. Provided with a thick layer of algae on the rocks, the fish will spend more time grazing and less time chasing, resulting in a more relaxed atmosphere.

The Substrate

Substrate is largely a personal choice as well. Sand or gravel can be used, but if you go with gravel choose a type with a finer grain size so that the fish can still dig, a natural nesting behavior that is enjoyable to watch. Sand is certainly closest to their natural substrate, and looks great.

Many types of sand can be used. Some, like finely crushed coral and aragonite (oolitic), can be bought for a fairly hefty price from the fish store and will help to buffer the water. Beware of cheap crushed coral as it may contain sharp fragments that can irritate the gills. The use of alternative methods for buffering the water will open up the options for substrate choice, and las with rocks many types can be purchased elsewhere for considerably cheaper then at the fish store. Beach play sand is an excellent source, being clean, attractive, and very economical. Pool filter sand is also a very good one. Additionally you can use river sand, concrete sand, construction sand, blasting sand and many other types too. Some are dustier then others, but all will settle eventually.

Only enough sand to bury any plants or decorations you may have is needed. Usually 1.5” is plenty. Over 2” is excessive and a problem of toxic anaerobic pockets under the sand can develope: when these pockets are disturbed and released into the water it can be harmful or even fatal to the fish.

Some mbuna are very avid diggers, and will keep digging right until they hit the bottom glass. One method of avoiding the ‘bare glass’ problem is to silicone a couple of layers of your substrate to one side of a piece of plexi-glass, cut to the size of the tank, so they can never dig down to the glass no matter how hard they try.

Lighting

As far as mbuna are concerned lighting is not very important. A single strip bulb will be dimmer and can help prevent algae. A double strip bulb tends to give the best lighting results, and allows you to mix and match different bulbs to achieve the most desirable lighting tint. More lighting will really promote healthy algae growth and gives ulitmate control of the color, but can begin to wash out the fishes colors.


The Water

To achieve the most accurate reading of your tap water, fill a container or bucket and run an air stone in it for a few hours. This will release co2 from the water and give a more accurate reading.

The ideal PH for mbuna is in the general region of 8.0, but they are very adaptable and can handle a fairly wide range. If your tap water falls between 7.5 and 8.5 you have good water, and are best off using it as-is, with no adjustments. More important is KH, which acts as a buffer and keeps the PH stable. A KH of 8 or more is most desirable.

If your water is not quite desirable for them then there are a few ways to bring it up to spec. Crushed coral can help, as can limestone and other mineral rich rocks. These can be used as substrate or decoration, and can also be placed in a filter. This method is great because more water is forced through the media then as a substrate, and it leaves you with free choice for substrate. Canisters are best for this because they hold more media then most types. The more finely crushed the coral is, the more effective it will be, but at the same time if it is crushed to a sand it will impede water flow.

Another option for an easy method is to use baking soda. If may sound strange, but it actually works very well and costs next to nothing. Baking soda will raise the PH to 8.2, and no further no matter how much you use. The more you use, the higher the KH will rise. The elements of baking soda do get used up, so it is important to check the KH weekly to make sure things are good, and add more if necessary. You also need to add more for the water that you replace at each water change. Even if it sounds a little complicated now, you will quickly get into the rhythm and these additions will become second nature.

You can also use store bought additives, but keep in mind many of them are unstable, and you would be no further ahead then using baking soda, and you’d be spending more money too.

Regardless of what additive, if any, that you choose to use, it is important to keep an eye on parameters regularly to make sure values are remaining stable. Test weekly and add more as you need to. In general it’s best to avoid all additives if you can. More often then not the water is suitable right out of the tap, and weekly water changes will keep it stable.

If your tap water PH is unusually low, less then 7, the best thing you can do for stability is keep fish that respond to that type of water better, this way you don’t need to worry about messing with the water parameters. There is no lack of interesting and aesthetically pleasing new-world cichlids.

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Read...The Mbuna Aquarium (PART 2)