I have a 20 gallon long tank with 2 FBT and 2 Anoles. I just put a piece of glass about 4 1/2 inches tall in the bottom so I could have it part land/water. I set it up and it looks great, but I don't know if I'll need a filter? I also have a Betta in the water section so if I don't have a filter, but change the water enough will the Betta be fine??? The tank has only been up for almost 2 days with no mishaps. I was planning on making a waterfall, but I didn't want to buy a water pump (for the waterfall) and then find out I needed a filter. I'll post pics asap. Will the water pump be enough to make it work? I'm planning on putting some java moss and a moss ball in the water....will that help?