Lastly I worked on the return line. At first I was going to run it with a bunch of 90 degree elbows, but after playing around with the wider elbows with the return lines I decide to make a 90 degree turn with two wide elbows to give it more of a gentle turn.
Here's the return line running up the back side and top. In the end I'm not sure if it'll make a huge difference in flow but I figured every little bit helps!
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One thing you may have noticed is that there is no check valve on the return! Honestly, I am not a fan of check valves. I've used them before and after time they just get gunky and don't close properly. Instead, I will be drilling holes into the back of my two return nozzles so that it breaks the siphon in the event of a power loss. I'm currently using this method on my 90 gallon tank and it works quite well. Yes, the nozzles can get plugged with gunk too but it is much easier to clean the nozzles than it is to clean the check valve.
Here it is snaking around the front end and dropping into the tank.
Something else you might notice is that I am not using bulkheads for the two return nozzles. I have the bulkheads for them but when I started working on it I quickly realized that the entire return line on top of the tank would have to be raised a few inches off the glass if I used the bulkheads. I didn't like this because then I would have to support the return line with something. Also, it would be a pain to reach into the tank on that side if the return line was higher. In the end I opted not to use those two bulkheads and just shoved the return nozzles right into the holes in the eurobrace.
So that's the plumbing in a nutshell. It wasn't rocket science but you do need to plan it out and remember to measure twice and cut once! Or, if you're like me, just run out and buy more PVC (but not from Home Depot because for some reason they don't believe in PVC).
Here are a couple of full tank shots to wrap up this stage.
