Just got the 25W UV sterilizer inline as well.
Damn thing leaked for the first three, four attempts but then with some Vaseline and elbow grease it installed leak free.
I have the W/D for most of the bio filtration and keep both FX5 units loosely packed as when I first got these was surprised how easy it is to overfill them and kill the flow rate.
Also when you pack too much media in these filters they become nitrate factories!!!
So one has Fluval pre-filter and ceramic rings with one 3" high flow foam ring and the second has ceramic rings, Carbon and a polishing pad. I am not a huge carbon fan but keep about 6oz's in one and rinse it out once a month.
The coralife UV sterilizer/clarifier makes the water look like glass!
I don't think I would have a tank without one after building this tank.
Now I just need to get my other tanks in this shape, well....and paint that ugly stand!!