Acaras are robust little Cichlids and in my experience keeping a few, if they decide the tank is theirs, they'll take it all. I haven't kept the electric blue morph, just the natural colouration ones, but they never behaved as some books said. They always fought and demolished tankmates. I don't understand their peaceful community rep, though I can say it appeared in books as far back as 80 years ago. So I would immediately get rid of them, or get them their own large tank where they can behave as themselves without tankmates getting harmed.
It isn't that they are overly aggressive. It's that we as fishkeepers make bad decisions on their tankmates. We live and learn, often painfully. I've been there and done that...
A breeding pair of angels won't share well either. Their egg and fry defense should be ferocious, although inbred forms like kois have often lost a lot of healthy instincts. A pair will test and retest each other at every spawning. I didn't realize you'd seen the acaras going for the eggs, and most likely, the female put up a good defense against bulkier, stronger fish. I have had pairs break up though, and I have had females or males killed when they weren't judged as strong enough anymore. Angels can be very expensive fish if you factor in buying tanks to keep them from murdering each other.
