The extra section is gonna be for a frag tank setup in the future. They had an awesome deal a a Deep Blue frag tank where I purchased the main tank but it was to long to fit the space. The wife even said you need to buy that! That is cheap. It was 48 x 24 x 12, I only have 38 inches of counter. Oh well I will keep my eyes open for a deal that will work.great job Duel. I really like the extra section ya built .