Time for an update. Not much has happened since the last one, but at least I'm getting the cycle started. The sump is full of water with a few loose rocks from the 90g and the display only needs about 2 brute cans full and I'll have it all running. Right now I have a return pump circulating water in the sump and one of my spare back up battery air pumps in the display until it gets filled. That thing has lasted over a week now on just the 2 D batteries in it. I'm impressed! Makes me feel a bit better about vacations, besides the heat of course.
So I've ran 2 brute cans full through my 90gal to get some tank water into the new system, and the rest has been freshly mixed saltwater. I don't want to disrupt my 90gal too much. One of the batches of water I made up just using RO water which gave me some ammonia to add. I tested it with 2 ammonia tests and had the Dome test it, and before adding the RO saltwater, the existing water in the sump had 0 ammonia and 0 nitrite. The batch of RO saltwater tested around 0.8ppm ammonia and after adding it to the sump, the sump tested 0.5ppm ammonia. About 24 hrs later it now tests at less than 0.25 but not quite 0 yet. That's okay though, the whole thing isn't even running yet and there's still time.
I also made a mock up of the canopy out of cardboard, so that's my next project as the tank cycles. The picture is pretty crude but you can probably get the idea.