I found an infestation on my broccolli and cauliflower.
at first I thought they were white fly - then upon closer inspection- with magnifying glass I saw that was not.
I've never seen this type of aphid/mite-
What kind of bug is this? What should I use to get rid of them? Neem oil? horitculture oil- animal fats?
Give em a day or two without food and then feed and see what happens. Sounds like between the heater, salt, water change etc that they may have had a bit of stress. If there is algae in the tank with them, they may be snacking on that when you are not around to see it.