PAFishMan, if you can could you test your water before you put it in the tank? Maybe your nitrates are just that high right from the beginning and I don't know what can really be done about it since I have never experienced nitrates that high. I know live plants will remove some and it might be a good idea to have some in your water but 160 is really high. Maybe the test you are using is old and giving a false reading?

Paul, can I ask why you are suggesting a mainly land setup for a mostly aquatic frog? Is it because of his water parameters or do you just like that set up better? I have seen some setups like that and I never understood it. Like I said I am far from an expert but from what I have seen these types of frogs really enjoy their water and spend most of their time in it and at least with mine they usually only come completely out of the water to hunt.