Live plants make a tremendous difference in an aquarium. Besides the fact (or actually my opinion, which I state as a fact) that live plants look better and the fish look better with them in a tank, live plants actually make a tank healthier for the fish. Live plants utilize the nitrates in a tank’s water as their source of food. Having good, healthy growing live plants in a tank will significantly help to reduce the nitrate level in a tank, and the lower the nitrates the happier the fish.
The two most common complaints about keeping live plants are that they fall apart and die, and they get eaten by the fish. This is often true for many plants that are sold in a local fish store—especially when said store sells plants that are not true aquatic plants. Even if a store does not sell plants that point blank will not survive underwater, many can be difficult to keep—with one exception: true aquatic ferns.
True aquatic ferns include many variants of the Java fern (Microsorum pteropus) and the African water fern (Bolbitis heudelotii). Java fern has a number of naturally occurring varieties, mostly having to do with the length and width of the leaves. There are some Java ferns where the leaves can grow as long as 10 to 12 inches, and others where the leaves remain short and squat. The “Windelov” variety, named for the famous founder of Tropica Plants in Denmark, has forked edges to each leaf. African water ferns come in a couple of different varieties, and they also will grow very differently depending on the water and light conditions.
The nicest things about both true aquatic ferns—Java and African water—is that they are virtually impossible to kill and they grow in any water/light conditions. The only important thing to growing these water ferns is that they must not be planted into the substrate. Yes, that’s right. Both of these ferns should only be stuck onto a piece of driftwood or rock, or wedged into a nook or cranny. They can also be attached to rocks or driftwood very easily simply by winding some black cotton thread around the fern to attach it to the rock or wood. It has to be cotton thread, as it will disintegrate over time, during which time the fern will have attached itself to the rock or wood. Fishkeepers can even stick a straight pin through the root (actually it’s a rhizome) to attach it to driftwood; the pin just rusts away.
These ferns will do well in any light condition, from low to moderate to high. They are slow growing, and it is recommended that there be some algae eating shrimps or snails in a tank with them, although many fish will nibble algae from the leaves. The leaves are apparently bad-tasting to fish, as there are very few fish that will eat them.