I would look into the Aquamaxx NF-1. It’s the best nano-skimmer I’ve ever used (and I’ve used my fair share). It’s silent, no microbubbles, easy to adjust, and is a beast. Only negative really is that the cup is really small. Pretty sure it would fit those dimensions.Tank is looking great so far.
Another skimmer question...do you know if you have the original one or the redesign? I was getting really close to ordering it but now I'm reading that they redesigned it at some point last year and it doesn't fit in the IM25 equipment chamber anymore. I'm having a lot of trouble finding a reliable answer. The redesigned footprint looks like its 4.5"x3" and the equipment chamber is only 4 inches wide.
Thanks.