Re: setting up tank
You can keep more frogs in a tank when they have more visual barriers and hiding places. Simple setups are okay, but they still ought to be living vivariums. Use live plants, put some driftwood in it so your frogs have something to climb over/hide under. It doesn't need to be super elaborate, but you sould have the necessities like living plants and leaf litter.
The water bowl is not necessary if you keep humidity up. Best way to do this is to avoid using a screen top and use something that limits air flow a little better so that the tank takes a lot longer to dry out.
Division: Frog Police