Nice job. I'm running something kind of similar. One piece of advice: When you cut your return section down to 2 or 3 galons like this, it doesnt take much evap to have a dry pump. Make yourself an auto top off, or you'll end up with a burnt out pump if you go away for a day or 2. (I have that issue right now.)
Also, paint the hoses, or cover them in tape or something. I have clear hoses..they fill up with algae because of the lights in the fuge.
Nice job though. Much cleaner than mine.