That is my Fluval Evo and is 13.5G although there is probably only half that in water volume in there haha. I actually downgraded from a 100G when I moved. Here is a pic of that one and even that one was getting small. I probably would never be happy unless I have my own ocean haha. You can see the yuma underneath that huge leather coral.
But in all honesty. Even though the bigger tanks are awesome, it did take more time with keeping it up and with my son (now 4) getting very active I love having the extra time to spend with him instead of cleaning a tank. It literally takes 5 minutes to do a water change on that Evo haha.