Quick Help with Adopted African Dwarf Frogs (Habitat)

[Plaz]

My daughters class has been studying ADFs for a month and is asking parents to adopt them. They did not give us a lot of notice... so her pair is coming to us in 5 days (Wed)! We have a 5 gallon and 10 gallon tank and heater. Planning to keep them in the 5 gallon with daily water changes until we can cycle the 10 gallon. Questions: 1) Is the "Exo Terra Flo 250, Complete Internal Filter" good for African Tree Frogs?.. or what other would be recommended (planning to make water level about 8" or so with sand on the bottom - unless different recommendations)? 2) What is the best fast method for cycling the 10 gallon or should we ask the fish store for some dirty water and wait out the 4 weeks? 3) Is spring water the best to fill the tank and for changes and would you recommend an additive? 4) Any really easy/non messy live plant recommendations - for after the tank cycles?

Thanks in advance!