Kuhli do not get 'pregnant' the females will get larger with eggs but there is not much you can do - on very rare occasions there have been reports of them breeding in tanks but it is almost always by accidents. Breeding farms use hormones to trigger breeding not something you want to use. As to tank size - i ahve a dozen in a 120 and another 8 in a 29 and 7 more in another 29. Is the tank large enough? Well bigger is always better as they can be very very active at night but for now that will ahve to do.