Tropical Plants
Hygrophila corymbosa "siamensis"
Written by Sunday, 29 December 2002 00:00
Hygrophila corymbosa is a plant originating from Thailand, specially suited for African Rift Lake cichlid tanks. It is a fast grower which can be used during the cycling of the tank or in large tanks where it forms a dense green forest. If trimmed regularly it will increase in diameter instead of height. The leaves are bright green and quite dense but if the plant is allowed to grow in height it will lose its lower leaves - something rarely desired. It offers many hiding spots for small cichlids - especially fry. The plant is extremely hardy; I have kept it successfully for 4 years now in a variety of environments ranging from cold water without any sort of fertilization (goldfish tank) to alkaline rift lake cichlid tanks with a high GH, a great amount of salts, with or without the addition of CO2. It will finally reach a height of 60 cm or even more at which point it is better to cut it back and use the tops to create new plants.
Hygrophila is not demanding as far as the lighting conditions are concerned; it may grow well with just one fluorescent tube (even a household one) although it does better with 3 or more tubes across the tank (full spectrum). For tanks deeper than 70 cm you should add one strip more. When allowed to grow above the water surface it will happily do so and produce blue-green leaves and small blue flowers. Fertilization, enough (good quality) light and CO2 will definitely increase its growth rate but, unless in a Dutch aquarium, the plant can grow decently with the bare minimum.
The plant has grown over the water surface while its diameter is over 30 cm. Because of the slow growth rate (no fertilization) the plant managed to keep a large part of its lower foliage.
The two fluorescent tubes shown here are a full spectrum daylight and a "plant" growth one. Both are placed 5 cm over the water surface. The water temperature ranges from 17oC in the winter to 30 degrees in the summer. Water changes are very sparingly performed in this tank (50% every two months). The huge amount of plants take excellent care of the nitrates.
Photos by the author.