So just about to upgrade my 15 gallon tank to a 20 gallon tank + 5 gallon "sump". . . but my friend just offered to give me back my old 29 gallon tank painted white (used to house some grow out discus). . . . I really don't want to scrape or repaint a tank right now. . . in your experience can a white background and floor look good on a bare bottom reef? Also my filtration and lighter were for the 20 gallon (16 inches high) would that cause any problems with the larger, and taller tank (18" tall) Light is 2 bulb 24W T5 coral plus blue plus????????