Love that rig man!

As someone who has himself wanted a power rig for a while, I have to respect the work you put into this beast, especially since a lot of the base design you've gone for here are very similar to what I've got in mind on my wishlist for my dream rig till I can get the cash for it.

Kudos to you man, really.

Also, as and when I assemble mine, the coolant I'm going for, a Thermaltake solution, recommends a flush of the entire loop with distilled water before inserting the coolant into the loop, which is what I believe you've done here. I was hoping to be able to ask someone with the experience before I was myself confronted with that task. How exactly do you go about extracting the water? Do you stick a syringe into the reservoir and suck it all out of the tubing, radiators and whatnot? And also, does it matter if any small portions of water still stuck in the system mix with the new coolant, or will the mix impact the loop or its components in any way?

Also, maybe your rig doesn't need this, but in case that coolant you're using has any water content in it, there's this antimicrobial silver strip available on Amazon that prevents microbial buildup inside the loop.

https://www.amazon.com/Silver-Coils-Antimicrobial-999-Strip/dp/B00A66HMRC/ref=sr_1_1?ie=UTF8&qid=1501854663&sr=8-1&keywords=antimicrobial+silver+strip

You basically just drop it into the reservoir, and its quite small (about an inch long) so it should fit into most designs.