Not sure if you are still looking for an answer to this... but I have had a RBTA clone for years, and it has split maybe 10 times so far. As far as I can tell, the best way to "get it to split" on its own, is to change the way it receives light... even if its only for a few days. Dont deprive it of light.... change the way it gets it. If it normally receives light from directly overhead, move it 45 degrees so it receives it from the side, etc... maybe not pointed at the nem either, just off center. Mine split in 1 day like this. I have done this more than once.