Even if you got rid of one of them, the single one may still need a larger tank pretty soon. I know it may look like there is enough room in there but aros (imo) a very claustrophobic. I've had to upgrade a couple different aros to larger tanks and their behavior change was remarkable each time. It was as if they were different fish the way they calmed down. There is still an off chance that you still may have a very skittish aro...But unless you do something, your issue with your aros will not get better. Good luck.