My Mom wants a fish tank for an end table by the window. I found a 16 gallon bowfront (she loves the curved glass) that would be good for the fish she wants. She will have at least 3 ottos (Im tryin to talk her into 6....) The tank will have a backing on it to block some sunlight but it may be kiddie cornered so obviously some sunlight will get in. Is this possible to maintain?