Finally got around to doing my second water change. The process is super simple and only takes me about 10 minutes start to finish now. I lay out my water hose and extension cable, hook up the pump to the top-off valve, and then I open up the drain on the return pump. As the water goes down in the sump, it trips the top-off which sends fresh salt-water from the tank outside. The temperature drops about 1 degree with the temperature of the water from the outside storage.
I also finally got the power supply controller printed. It took a couple of re-designs to make everything print. I think part of my problem is that ABS shrinks and also that my printer prints a little on the small side (about .5 mm per side on a 20mm print). I still need to calibrate my printer’s axis.