Planted Tank Guru
Join Date: Dec 2013
Location: San Francisco, CA
Do you really mean right-left or left-right? If right-left, that will look odd. EDIT: NVM, slopes UP from r-l. Since there are plants there, it wouldn't matter.
The front line must be level like a picture frame b/c it frames what's inside the tank. Anything else causes the eye to focus on it.