Do they breed best in trios or pairs?
I breed them with pairs, trios and at times more. Some in the USA say that pairs are best as the spare females dont follow the spawning female through the mops and eat the eggs as they lay. Use thick mops and that will make it harder for the hungry ones to follow.
whats the best thing to make a mop out of?
make it out of synthetic wool... not natural wool as it will rot. Dont be supprised if the dye comes out but it dosnt seem to harm the fish
Also would an 11 litre with a sponge filter be ok?
yes