Since this tank was freshwater and I was going for low(er) maintenance, I opted for auto water changes.
I bought a solenoid off ebay for $12 and hooked it up to my incoming water line. The solenoid is plugged into my auto top off / float valve system. When the water level drops, the float switch makes contact and tells the controller to turn on the outlet for the solenoid. When the solenoid gets power, it opens and water flows through.
I realized that I hadn't dealt with chloramine yet. I didn't want to add water conditioner as I planned on adding fish later. There's much debate about running carbon in a filter for a freshwater tank. The general consensus is that carbon will strip out fertilizers and chemicals beneficial to plant growth.
The solution I came up with was to re purpose my Bulk Reef Supply dual reactor. It was meant to be run in a closed loop with carbon in one container and GFO in the other on a reef setup. I took it apart, cleaned it, replaced the fittings to accept my incoming water line and stuffed both reactor chambers full of carbon. Now any incoming water from the tap to fill up the tank is forced through an absurd amount of carbon stripping out the chlorine and chloramine. Yeay... filtered tap water to keep the tank full.
You can see the incoming water on the left with a shut-off valve, the solenoid, and then into the reactor (all on 1/4" polyethylene tubing). After the reactor, I just used a piece of 3/8" PEX to bring the water straight into the sump. At first I used more 1/4" tubing for the return line, but the water pressure (remember this is at house water pressure 70+PSI) caused the 1/4" tube to want to fly around. I anchored it but was afraid it would come undone, so I swapped the 1/4" tubing for the pex. Works like a charm.

For the auto water changes, I took a maxijet 1200 utility pump that I had laying around and hooked it up to the Digital Aquatics Reef Keeper Lite controller for this tank. This is the same controller I use on the turtle tank to automate things. I've become so dependent on these controllers, I couldn't imagine running a tank without one. So the output of the MJ1200 pump is plumbed with 1/2" PVC to a nearby floor drain in my basement. The MJ1200 is rated at 295GPH @ 1 foot of head. I only needed to raise the water about 1' to go up and over the side of the sump.. so this pump should be putting out close to its advertised 295GPH. I setup my aquarium controller to turn this pump on 4x a week for 1 minute. 295GPH/60minutes ROUGHLY equals 5 gallons of water if this pump runs for a minute. My total system volume (75G tank + sump) is about 100G. I'm changing out roughly 20% of my water every week on this tank. So the pump turns on and pushes the water out down the drain. The water level drops, and the auto top off float switch described above turns on. About 20 seconds after the water starts pumping out.... the top off system begins to replace the water with clean filtered cold tap water.
And no more manual water changes for this guy. *happy dance*

Here's the controller. If you'd like to know more about it, visit Digital Aquatics here:
http://www.digitalaquatics.com/