Just tested the water for ammonia and nitrite. Ammonia levels are zero or close to zero in both tanks, it looks like nitrite is at least 2 ppm in my 28-gallon (clawed frogs), and 4 - 5 ppm in my 10-gallon (dwarf frogs). This is using API test kits. I will test nitrate later, but expect there to be at least some due to I put media from cycled tanks in the filters. My tap water tested at 5 ppm for nitrate.

I'm going to the LFS and seeing what they say about this and my fish issues, and go from there. Yesterday's frog death hit me hard, especially since I feel I have been trying my best to address the water issues when I found out about it, and trying my best to make sure all frogs eat.