I'm going to get a whites tree frog soon. I'm going to have a 15 or 20 gallon tank with 2-3 inches of water (3-4 gallons) on the bottom.
I don't want to change the water every day, so I'm assuming that I'll need a filter. I also heard that moving water increases humidity. I would prefer a small, simple to use, submersible filter. Does anyone have suggestions?

I bought a 10-20 gallon UTH and a 13 watt 5.0 uvb bulb. Will that heat the tank properly? I didn't want to get a heat lamp because it dries out the tank.