If you are thinking of starting or expanding a planted aquarium, Java fern is an excellent plant to start with. Its full latin name is “Microsorum pteropus” and is a very easy to care for plant which is extremely popular.
There are several reasons why Java Fern is such a popular plant. The primary reason for this is simply that is is extremely versatile and very easy to keep. Both rooted and unrooted forms of the plant can survive in an aquarium, with the unrooted variant eventually attaching to driftwood or gravel given enough time in one location. it is often ignored by fish which would normally be detrimental to plants, due to its bitter taste. The combination of these two factors make it suitable for most aquariums and all kinds of fish.
Java Fern is sensitive to high intensities of light, doing best in low-light environments. Low to medium levels of light are also beneficial for preventing the growth of both cyanobacteria and algae, with the later using light to form food via photosynthesis like all other plants. Aquarium plants directly compete with algae for food and in doing so, can help to starve algae of the nutrients it needs to grow. This means two things for you as a fish-keeper; firstly that Java Fern can do well in even poorly light aquariums and secondly that you are less likely to have to worry about algae.
Whilst it is worth taking note that Java Fern grows very well, it does not tend to grow so sporadically that it will overtake an entire aquarium. It will grow in the dimensions of twenty to thirty five centimeters in length and between twelve to eighteen centimeters in diameter. The amount of growth experienced is based on the conditions the plant experiences, namely light and water conditions with Ph tolerance being neutral.
It is not advisable to directly plant Java Fern into gravel as they will rarely root there. Unattached ferns may settle down into gravel or substrate of their own accord and it is not impossible for Java Fern to root into gravel, albeit an unlikely occurrence from direct planting. It is worth trying to encourage Java Fern growth particularly if you care for live-bearing fish or intend to breed them.
Java Fern will do well in most conditions, it is important to provide a good quality of water for them as it is for fish as well as making sure they do not get too much light. The condition of the leaves is a good indicator of if they are exposed to too much light as they will be discoloured. They will also do well in aquariums where there are a lot of rocks and wood as this is what they normally attach to in natural environments.