I have a ten gallon tank filled to 4 inches of water,
a sponge filter (turned off), an adjustable submersible heater, live floating plants, an indian almond leave and half a styrofoam cup in one corner attached to the glass by tape.
Here is a pic of the tank
The tank was set up and let run for a week before introducing the male, left him in one day and then put the female in a glass chimney about 3 inches from the cup.
The male blew his nest the day I put the female in, they were together the whole day around 12 hours but did not spawn.