Encouraging Cory aeneus to breed?

[beta123]

I have 4 albino cories(2 male, 2 female), which laid egg once a year ago & none hatch Now, I want to get them to spawn again. The problem is I want to use plain tank without gravel for easy cleaning. Has anyone try to breed cory without gravel or sand?

 

[leighasnana]

I've got albino fry in a breeder trap without gravel. I clean the bottom a couple of times a day with a Q-tip.