I have 4 old Zebra Danios in a 30 G tall and 2 surviving neon tetras in a 20 long. Can I put the Danios in the tank (20G) with the neons or will they fight? I would really like to take down the 30g as it is not in a convenient place and was set up as an emergency tank to take the danios when their owner moved. I understand it's preferable to have a school of each, but I am having trouble keeping a school of the neons - and right now for some reason they are difficult to find and fairly expensive if you do find them, so I prefer not to try to start another school. However I don't want a fish to get hurt because it isn't a compatible species.