I have 3 Pearl Danios, one I suspect to be female. Now the 2 I think are male keep slapping each other in the face with their tails. Could they be competeing for her? Also I read somehwere that if you want to breed Danios you must lower the water level to 5-6 inches and have a wack load of live plants. Is that true? If so what is the likelihood of Danios breeding in a tank not set up for it?