If I were you, I'd leave the singing adults (loud as they are, but think of all the skeeters they eat) & raise up a couple-few babies from tadpole or tiny toadlet stage. That way they don't come into captivity having known about the whole big outside to wander... it seems somehow kinder to me.
Tiny little toad babies can eat dusted/gutloaded pinhead crix & flightless fruit flies...rule of thumb, feed stuff no wider than their heads. Tadpoles can graze off algae-covered stuff from your pond & live in pond water, if you change it fresh every day with new pond water. Tadpoles can live about one tad per gallon, & when they have 4 legs they need something to climb onto, up out of the water. 4 legs = no more gills for tadpoles, they have to use brand new lungs to breathe, then.
I kept Edmond (adult toad) in a 20 gallon (used to have 2 but Clive died last year, unknown reason), with ~3 inches or so of moist coconut fiber (bed-a-beast type stuff) over terra-lite for drainage (look at blackjungle.com about that stuff). Live plants planted in the coco fiber get fertilized with toad poop, nothing's easier. GC toads like to bury themselves in the substrate, backing their butts down into it. Coco fiber is good for this. They also like low-ceilinged, snug little hidey-holes to go under, especially if they can hollow out the soil underneath a little.
Plants like fluorescent lights over the screen lid...2 is better than one. 12 hours on, 12 hours off. Judge temp by what the outdoor guys have; it may be hot, but these are burrowing, shade-loving guys, so if I was cool enough to use long sleeves I turned on a heat lamp (on one end of the tank, for a temp gradient) but didn't worry much otherwise.
Crickets (I fed ~6 a week) get dusted with rep-cal or rep-vite supplement powder, & gut-loaded fresh nutritious veggies, or store-bought cricket bites. Waxworms are a popular occasional treat (all fat), but mealworms keep chompin too long after they've been swallowed, so don't offer those. Edmond never ate an earthworm when I offered em, but it's worth trying.
I liked a dish deep enough to cover Edmond's shoulders with water...I used a ramekin (sorry mom). He looked real cute in it, often sat in it with one arm propped on the rim, like a fat guy in a jacuzzi. Change the water every day, use water aged 24 hours to leach out chlorine, if you're on city water. They usually poop/pee right into the water, so change it daily even if you can't see any 'foreign matter'. I had Edmond's dish embedded in the coco fiber, so I used a (toad only) turkey baster to suck out the water, rinse, empty & fill again (& just water plants with it or dump down the toilet if it's too moist to water plants anymore).
You can have a lot of fun landscaping & creating a little environment for your toad(s). When we lived in SoCal, I got the toads & built the terrarium because I missed the ferns/moss type environment of the northeast, so it was a little oasis on my bedside table, & there was always interesting stuff going on in there. Good for taking imaginary walks in a mini garden. Edmond & the rest of the critters moved 3000 miles back east with us last summer, & now we've got 17 acres of REAL woodland, with salamanders & newts & painted turtles & deer....but I still love my bedside garden. Just wish Edmond was still in it...(see last post for info on his death.)
I'm in MA & never lived in GC Toad territory, so you probably can glean more info about their ideal environment yourself; I just bought mine in a pet store (labeled Egyptian Toads, no less) & did the best I could with research.
Have fun...maybe make a naturalistic non-chlorinated pond for the locals?
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~kimhotep 
