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.
The blooms of non-toxic algae can also create problems when the algae die. The dead algae sink to the bottom where they are broken down by microorganisms through a process that depletes oxygen in the seawater. Low oxygen concentrations in the water can lead to large-scale mortality of fish and crustaceans.