Oh yeah...lol I made this mistake before. I got a 12" wide tank to be the sump and forgot to measure the inside part where there were braces. There it was 11.5 inches. So close, but I had to get a carpenter to replace the the braces with smaller ones and in doing so he cut the entire back brace off and have screws to put it on or take it off. That's how I got mine in, but without the 2 problems, I wouldn't be able to get such a large sump. What are the dimensions of the skimmer and the reactor is for carbon?..GFO
?..dual reactor w/ both?...You can leave it out of the sump and put it behind the tank if it fits or on the wall in the stand or wherever else.