While your fish may not get eaten right away because the frogs are still small, your fish may become overstressed and not do so well as long as the frogs are in the tank with them. I would definitely separate them sooner rather than later. Exactly how big is the other (kids) tank that you have? It might be best to move the tetras and blind cave fish into the smaller one-if it is an acceptable size-and use the bigger setup for your frogs. This will give you enough time to save up and find a permanent, bigger, home for the frogs, and then your fish can have the 17 gallon back. Best of luck and if you have more questions, we are here to help.