Bill, that's a very good comment about the pump. Ultimately, it does seem wasteful to add in that MD 700. Max flow rate for my UV is like 560(or around there), so if indeed the MD 700 is able to pump over 560, then my UV is hindered, or pointless. And, the energy concern is valid.
However, I *need* the MD 700 to drain the tank. I have to go up 7'10" to get to a drain, and the Eheim's won't do that.
Your comment makes me consider redesigning and putting solenoid A and the MD 700 inline together, and hooking them up to the controller together, so that MD 700 turns on when Solenoid A opens so it can drain the tank.
Serious consideration (and the full consequences of) will have to wait until tomorrow
By design, there will be no powerheads in the tank. I'm with you, normally, on plant growth covering up wires, but I'm not planning on this being that dense of a tank, so they won't be covered up. The decision to include an over the back loc-line was a big one. I also had to make a tremdeous sacrifice for my water change system, which will use an in tank micro float switch. It will be minimally invasive, but even that was a severe concession. The alternatives to the float switch were relatively cost prohibitive.