An AC110 could be good for a 110g. It just depends on the bioload of the tank. A heavy loaded tank will obviously need more filtration. If you had a 110g which is mostly planted with only a few small schools of tetra's or something similar then a 110g would more than likely be good.
I usually run two AC110's on a 50g - 75g but my stock list is usually on the heavy side.
125g - FX5 - CF500UV - Bichirs - Catfish - Clown Loaches - Oddballs
40g Breeder - Fluval 306 - HW402B - Grow Out Tank - Clown Loaches - Leopard Leaf Fish