Aquarium plant from tissue culture in closed cup.

The genus Eriocaulon is usually adapted to soft water. Eriocaulon cinereum is more tolerant than most and will thrive in medium-hard water.  Soft water will promote overall health.
This is a quite small, very narrow-leaved and almost cushion-growing plant, that demands good supply of light and CO2 to develop. 
The plant usually flowers very willingly after planting in the aquarium and the numerous flower stems give a unique appearance. 
Flowering easily drains the energy of the plant, but given the right conditions, it will gather new energy and grow from basis after some time.