I didn’t think about the access with the tank against the wall. I'd definitely cut the top of towers off for access then.
or....
You could look a custom acrylic filter insert, similar to the fiji cube inserts. I'm not sure where to look for that but maybe one or two of those would be close to what you need. It could be an easy DIY build because it wouldn't have to be absolutely water tight because it would be in the tank.
or....
You could look a custom acrylic filter insert, similar to the fiji cube inserts. I'm not sure where to look for that but maybe one or two of those would be close to what you need. It could be an easy DIY build because it wouldn't have to be absolutely water tight because it would be in the tank.