Well I'll reply to the parts individually here.
"hello
i am interested in getting a pixie frog, can anyone give me a little insight on them? i was going to start him/her off in a 20 long with peatmoss as a substrate with undertank heat pad and aquarium lighting, and i'd use mineral supplient on the foods, my questions are, how big do they get exactly? are there didderent sizes based on locailty? I've seen some articles saying an adult size of 4-6 inches i've seen some saying 8-10 inches which is the correct one??
i was plannin on moving him/her into a 40 breeder or a 75 gallon whats the space requirments for a full grown pixie anyways?? "
thanks in advance for your time
James
Ok, do not use an undertankheat pad use a heat lamp, these frog burrow to get out of the heat and may burn themselves in the porocess on a heat pad.
The males are the bigger of the species and there are 2 species the dwarf african bullfrog only gets about 5" max no matter which gender it is, the normal african bullfrog males get up to 9" and females up to around 6".
And I use a 40 gallon breeder tank for my adult male african bullfrog, which is big enough but I am still looking into getting him something bigger.
Just make sure you get the proper species of african bullfrog or you may be very dissapointed with them. The dwarf african bullfrogs keep some coloration which to me makes it ugly but the african bullfrog goes to an alomost solid color. If you need help discerning which is which just ask me.

-----
http://joshmilliken.tripod.com/