Hello all! New to the forums. Just got my L2 a few weeks ago. I'm not necessarily new to the reef game, but definitely new to using an ats. My last build was about 10 years ago, n somehow I ended back up in it. here's my build ...so far. My filtration will be ATS only. I built some mounts out of acrylic to countersink the ats about 1/2" below the rim of my sump, so I have just enough room to service it. It's definitely a tight fit.