Yes size of tank and its dimentions are very important.
Being that it a corner tank that makes it a bit harder to light due to its shape but still possible.
With out knowing more I would say that for what you describe being mushrooms and leathers and polyps that a muti bulb PC
lighting setup would be fine for you. The number of bulbs and the wattage of those bubls will depend on the size of your tank and its measurements front to back and what it measures ast its widest.