There is no way to know if your plankton bloom will diminish or intensify over time. Having some green water is very good, but having a very dense plankton bloom can be potentially risky. Treatment with copper will kill phytoplankton, which dies and decays, releasing nutrients that can be used by plankton in the following days. The best way to deal with dense phytoplankton is to deal with the conditions for dense plankton growth. Try a microbial water clarifier to manage nutrient concentration, along with a dye like aquashade to limit sunlight penetration. Stop the copper application. This should improve your situation, but will take time. Learn to like the green water, but you want more than 12" visibility.

It's ALL about the fish!