Yep. I would have had to do that to my Aqueon 75g as well to get AC75s to fit properly. I think I bought this tank new in 2013. The only HOBs that fit it properly are the big guys like AC110, Seachem tidal 110 and the biggest marinelands. I've had a Seachem Tidal 110 on it for about 2yrs. Don't care much for this HOB, but it works and I don't want to buy another. LOL.