I currently maintain a small, sideline aquarium maintenance business. After I began this service, it soon became apparent that while my customers wanted fishes as colorful as those on a coral reef, they did not want to pay for marine tank filtration systems. Additionally, they wanted "pretty plants," and plenty of fish to go along with them.
Plants and heavily-stocked tanks are nearly impossible goals with salt water set-ups. I came up with a solution which satisfies my customers; I combine rainbow fish from Australia and New Guinea with Lake Malawi cichlids. Additionally, I use aquatic plants and driftwood to decorate the tanks.
I like to use Turquoise and New Guinea Red rainbow fish for top water dwellers, and Labidochromis species, Electric Blue Haps, various Aulonocara (especially jacobfreibergi), Crytocara moorei, and other Haplochromines for the bottom and middle of the tanks. By avoiding the more aggressive mbuna, such as Pseudotropheus and Melanochromis, aggression is kept to a minimum - which is important, considering the reason my customers wanted an aquarium in the first place was to keep clients calm while they wait!
When I do the twice-a-month water changes, I add baking soda (sodium bicarbonate) and Epsom salts (magnesium sulfate). The pH in these tanks ranges from 7.6 to 7.8, and the DH is more than 200 ppm, which suits both rainbows and cichlids just fine.
The plants I use in the tanks at my accounts, as well as the ones in my home, are Vallisneria gigantea (or a hybrid thereof), Java Fern (Microsorium pteropus), Bacopa caroliniana, Java Moss (Vesicularia dubyana), Cryptocoryne wendtii, and Riccia fluitans. For my personal aquaria, I use the same water for my Lake Tanganyika cichlids as I do Malawi cichlids. The plants mentioned above do equally well with both groups.
Purists may believe the only way to keep rift lake cichlids is by using rocks as cover. However, a stand of Vallisneria with six-foot-long leaves provides an amazing number of hiding places, while the leaves overhead give fish a sense of security, which keeps them in plain sight. Likewise, fish find comfort in a dense growth of Java Fern. Also, a many-branched piece of driftwood, overgrown with Java Moss, provides shelter for both adults and their fry. Plants and driftwood weigh considerably less than a rock structure. And it is infinitely easier to siphon debris from under wood and around plants than from under a pile of rocks. Additionally, plants act as living filters, neutralizing waste products while giving off oxygen.
Aside from a preconceived notion of what a African cichlid aquarium should look like, there is no reason cichlid fanciers can't enjoy the beauty of a planted aquarium. As long as the basic tenets of aquatic horticulture are adhered to, the high pH and hard water of a rift lake biotype should be no barrier to successfully growing aquarium plants.