If you're talking about Dendrobates Azureus then I woulld have to say a 1. You dont really have to do anything ...they make their own babies. It is vital that you start with a fully grown male and female. I feed mine a lot ...I'm not sure if that helps but it keeps them fat and I dust the food with vitamins and calcium. Petri dish under the coco hut and a water source for them to put the tads in. Mine is a puddle because I'm lazy and haven't drained my tank lately but you can use a small dish or shallow deli cup. I just wait for something blue with legs to crawl out of the puddle. You know you're real lazy when you've got four or five little ones running around the tank and you spot them when theyre a month old. So if you want a lot of them pull the tads and they"ll make more. Or just let the frogs do their thing and scoop out the froglets when you spot them.