My molly fry dont seem to be growing very fast. They are about 5 weeks old and still just about 1.3 cm long...one of them is even smaller. I feed them a good flake food that ive ground up myself and they also get bloodworm, spinach and peas. I thought that by now I would be able to put them into the big tank but if I do that I think they will be eaten. Am I doing something wrong?