When you have an employer group health plan and want to apply for Medicare, the work status of the policy holder (you or your spouse) affects whether or not you will be in a Coordination of Benefits period.
Copper is an excellent treatment for saltwater ich or marine velvet disease, but it can be toxic and stressful to fish. Of course, using it is much better than letting a fish die from velvet, but it should never be used in a tank with healthy fish. Improper nutrition is also a commonly overlooked stressor of fish.
A bloom does not have to produce toxins in order to be harmful to the environment. It can also be harmful by causing anoxic conditions where oxygen is depleted from the water. Blooms can block light to organisms lower in the water column, or even clog or harm fish gills. Not all algal blooms are harmful, some can actually be beneficial. Phytoplankton are found at the base of the marine food chain therefore all other life in the ocean relies on phytoplankton.