Do I need to put each of these plants in a separate container? Or perhaps a couple to a container?

They seem to be doing OK, except for the size of the peppers. The plants themselves are about 7 to 9 inches tall with a canopy of about the same measurement.

I bring them inside at night for warmth and return them to the outside for sunshine during the day. I had considered bringing them inside and using a grow light. But have read that this is not really optimal for them.

Any information would be greatly appreciated!

Thanks,
Shelley

Those plants are most likely WAY over crowded. I haven't grown that particular type but my experiences with Anaheim and a few other chili pepper plants are that a pot that size would only support 2-3 small pepper plants. I did a quick Google for info about the Aji Dulce and one site says they should start producing peppers when they are about 18-20" high. So yours are only half the size that they should be. Plants can get up to 4 feet high but that's probably only in ideal conditions after a few years.

My experience has been that chilis in smaller pots will start fruiting at about the same time (or even earlier) as their brothers in a bigger pot, but the number and size of the peppers will be fewer and smaller. That sounds about the same as what you're experiencing.

I'd plant 1 chili each in a 12" pot, bigger would be even better IMHO.

Good luck.

Susanne