Here's that gap...
It's about 6-7mm. To be fair, to get a 30cm gfx card in a case aligned like the fortress FT02 and get a triple rad and fans isn't too bad.
Slightly prettier but I'm not a modder....
I'll get a UV tube as i'm pretty sure the tubing is UV. Didn't want to bother with dye - I've heard it can be a factor with sludge in the long run?
And 6 hours gone - no signs of water - at all (except where it's meant to be!). I'll keep checking but im thinking it's safe.....