Hi Michael, thanks for your interest, I went through your blog, looks like you got a good deal. :) Good job on cleaning everything, those first pictures looked pretty scary. When you're done it looks like you're going to have a showroom piece. Just to clarify the controller isn't Pi based, it uses two 32bit Arduino Due's, these are the fastest available. One arduino runs the display and one runs the controller.
Assembling the controller is fairly straight forward, some basic soldering is required for a few internal patch cables but there's an option on the kits to have this done.
To run the mars aquas you'll need a signal converter board as these lights are 0-10v, apparently some are analog and some PWM but the converter can do both types. The controller LED channels put out 0-5v PWM signal. You'll have to open the lights and add the converter internally then run the signal wire from the controller to the light. Here's a link with a little info that might help. I have the converters in 4 or 8 channel.
https://www.robo-tank.ca/forum/Thread-16...94#pid1094
The Fluval SP6's won't be a problem as they are AC, you just need to factor in the power bar can only handle 10amps max, looks like you have a lot of large pumps. You could build it using two 4 channel relay modules so you can have 20 amps max more than your wall can probably handle. :)
The Jebo DCT9000 would require additional hardware because they draw about 2.7amps on full, the max the controller board can put out is 3amps and 1-1.5amps is already being used for display etc... I have external boards with mosfets that can handle a bit more power and could be put inline. Currently the code is only setup to turn 4 DC accessories on or off but the ports are capable of adjusting speed I just need to get that feature added.
The controller doesn't work with the Atlas Scientific dosing pumps, flow meters or ATO, only the PH, ORP, Dissolved Oxygen and Conductivity circuits.
For dosing pumps you can use any standard 12v pump, a lot of people use this style because its cheap but there are better quality ones available. These connect directly to the controller and it'll turn it on/off.
https://www.ebay.com/itm/Dosing-Pump-Per...SwjS9ZiWeT
For flow meters here's one I found for 1" that should work, it needs to be similar to this.
https://www.ebay.com/itm/DIGITEN-G1-Wate...0505.m3226
The controller does have a good ATO system built in. It uses 2 float switches, one is for monitoring level, another for backup. There's also a timer backup system in the code that will still shut off the pump if both sensors fail. The main float switch can also be any Arduino analog water sensor if you so desire. You can also use custom rules to turn on the DC accessory pumps using digital or analog sensors.
Mounting the display in a cutout can be done however I don't have a bezel but could design and print something out for you similar to this.
https://www.robo-tank.ca/forum/Thread-Ni...in-progres
If you have more questions let me know.