"Corydoras bilineatus was collected in Bolivia, Departmento Santa Cruz, Cochabamba and Beni, system of the upper Rio Marmoré. 14°-18°S and 62°-68°W at an elevation of 161-327 m above sea level. The typus locality was a large standing pool in October 2001 with dense floating plant cover of Pistia stratiotes, Eichhornia, and Salvinia. The roots of Pistia serve as substrate for egg laying. C. bilineatus from the typus locality live in relatively cold-water temperatures of only 18-22 °C (64-72 °F). In contrast, specimens from the Northeastern low lands (Trinidad) live in temperatures that about 3° C/F higher. The pH ranges from 6.04-8.40 with 20-1000 mS depending on locality. C. bilineatus occurs in rather large groups that contain hundreds of individuals."
If you want to simulate this habitat, you'll have to forgo your original plant choices in favor of floating plants, but it will be a very easy tank to maintain and the dense floating plants will help remove nitrates from the water.
I would recommend a substrate of fine sand, a few rocks and nice pieces of driftwood, fallen leaves if you want them (but not tons). and a dense canopy of floating plants. Eichornia and Pistia get too big for a 20L, so I'd go with Salvinia natans.
Last edited by kuni; 01-25-2012 at 06:06 PM.