Amanos do not eat healthy plants, they only eat dying plant materials and biofilm, unless they are REALLY starving. But you said you feed a lot of brine shrimp, do you feed any plant/veg based foods?
Remember how I said don't change more than one thing at a time also? Removing your algae eaters is another change. I wouldn't be surprised if you start seeing algae now. But time will tell. Good luck finding your balance, it is a tricky thing but just keep trying.