Personally I would just let this batch develop naturally and see how it goes.
I've spawned a few batches from my Green Terrors and honestly the parents do a much better job than we can do. That being said, if the Dempseys start showing interest in the fry then you probably need to separate them if you want to develop the fry.
I've spawned a few batches from my Green Terrors and honestly the parents do a much better job than we can do. That being said, if the Dempseys start showing interest in the fry then you probably need to separate them if you want to develop the fry.