I agree, once your vicious hunters the ladybugs take care of the aphids, that should fix your problem with the ants. It's a bit of a waiting game. If you find more hunters in the house, bring them to the aphids.

On your algae, from what I've read, you want to make sure the tops of the rocks don't get submerged. I think you want about an inch of dry rocks on top. Some of those cups need to be topped up with rocks, the more empty ones have the most algae. And maybe add a ring of tape or string to your cups to hold them a little higher. Or maybe a thicker float pad would be better. Or glue some foam pads to the bottom to float this one a little higher.