The densely packed small black spots on the walls of the shrimp tank may be brown algae, a water quality problem.

Brown algae is one of the common algae in shrimp tanks. It will form a layer of black spots on the tank walls. This is normal algae growth and can be treated regularly with a water purifier containing high-quality biological bacteria.

The water quality is poor or ammonia nitrogen, nitrite, etc. exceed standards: it is recommended to change the water in time to improve the water quality environment.