It takes this long to clean l----------------------------------------------------------------------------------------------------------------------------------------------------------------------------l
In my 20g, the gravel is about 1 1/4 inch in the front and goes up to 2.5 inches in the back left and I have a hill in the back right corner that slopes up to 3-4 inches. No offense, but is that important? I have an undergravel filter for right now(plan on upgrading to a canister filter and keeping the ugf) I generally syphon one half of the tank every water change(which is about every four days).
mine is about 1 and a half inches though out my tank but with a few hills and stuff in between and i do have gravel in 2 corners around the plants to make it look different !