Hello Michael,
Now you did not state the size of these. For smaller 3-4cm you could add more, however please be wary that when then get to teenager/adult years there will be struggles and fights occuring.
I am not at all in favour of a 70liter tank, because a lot of people buy fish small and then do not get larger tanks when the fish mature and then have problems with injury and illness due space stress.
So what size BN do you have and what size Peps do you wish to get ?
cheers jk :thumbup: