Minimum Tank Size: 5 Gallons
Care Level: Very Easy
Water Conditions: 5.0 – 8.0 and Soft to Hard
Temperature: 18-30 °C (70-75 °F)
Java Moss (Vesicularia dubyana) is one of the easiest to grow of all the commonly available aquatic plants. It’s hardy nature and striking green coloration makes it a favorite among aquarists, and it can be found in aquariums throughout the globe.
Originally found in Southeast Asia, it has now been reported as an invasive species in several tropical climates. In fact, many people consider it an invasive species in the home aquarium, since it can frustratingly difficult to remove once established in an aquarium.
Java moss is especially sought out for breeder tanks, as it provides numerous benefits to the tank. The densely growing moss provides a perfect refuge for any newborn fish and it also has the added benefit of providing food to the tiny fry. Numerous types of microscopic infusoria live on the long tendrils of moss, and provide a veritable feast for the hard to feed baby fish.
Growing Java Moss is incredibly easy and unlike many of the more finicky plants, it doesn’t need any special lighting or added nutrients. It will even thrive in aquariums with very low lighting, and may actually start to suffer if placed in aquariums with overly bright lighting. When placed in a brightly lit aquarium, it usually becomes blanketed in algae, and may eventually die if it becomes totally covered.
Adding to the ease of caring for Java Moss is the fact that it doesn’t need to be planted. To prevent the Java moss from constantly moving around the aquarium, most people with attach it to rocks or driftwood. It also looks visually stunning when formed into a moss wall, which can be accomplished by pressing the Java moss between two pieces of mess and attaching to the back of the aquarium.
Attaching the Java moss to rocks or driftwood is easy, and can be accomplished by either tying it down with fish line or a dark-colored thread. Some people also have success using flexible meshes, but you need to ensure that any mesh used is completely non-toxic. After at least one month of growth, the Java moss will anchor itself and the fish line or thread can be removed at that time.
The propagation of Java moss is as simple as breaking off a piece of the moss. It propagates through division, so any piece that is broken off will continue to grow and will form another large and dense bunch of Java moss.
Java moss is something of a rarity, as it is compatible with nearly any species of fish. Hungry goldfish will leave it alone, and even constant movement around the tank courtesy of large cichlids won’t kill it. In fact, there are nearly no reports of any fish enjoying the taste of Java moss, so it is safe option (if a tad messy) in any fish tank.