I've had success with the target.

I've always thought of them as horses, each one needs at least two acres of land (or whatever the amount is). In another fashion, you don't put five on one acre.

The second thing is that you need a sustainable population of pods. I would caution that a small tank, along withe addition of a large population of pods may not have a large population at the end of the month. Half may die off if they can't eat.

My benchmark, and I've never added pods, is shining a light in the overflows. When I saw a significant population there I waited a few months before adding the mandarin.

I've never got mine to eat, and in hind sight had I known that it would live solely off the pod population I would have gotten one of the phsychos.