Adding another display tank to the system.....???

[bloat]

I'm pretty sure my sump can handle the extra water incase of a power outage......and I can get an extra pump in my sump to drive water to the new tank.....I just don't know how to let the water flow from the new tank to the sump, since it will have to travel against gravity up about 6' before heading back down to the sump again......