My son and I have 2 African Clawed Frogs from Grow a Frog that we raised from tadpoles. (They are young, morphed in May). After researching, we have upgraded to a larger aquarium with a filter. I always use spring water and they have been doing fine in the unfiltered spring water. My question is, do I need to "cycle" the tank if Im using spring water? Or can I just add them to the water like I have been doing since we got them. Also, how necessary is a tank thermometer? The tank came with one but they have been doing well without. Thank you for your help!