I also think that the ants are probably there because of the aphids.
One suggestion that I would make is to use a thicker piece of foam board for your floating net cup holder in the sump. I would go with inch and a half foam board. It will hold the netcups further out of the water, but the bottoms of the netcups will still be submerged, so you won't have any problems with the plants drying out.
I wish I could get ladybugs in my greenhouse in the summer time. :-)
Don't forget to post this to your patreon page. :-)