undergravel filter

An undergravel filter is a type of aquarium filtration system placed beneath the gravel substrate. It works by pulling water down through the gravel with a plate and uplift tubes, then filtering it through the gravel layer, which hosts beneficial bacteria that break down waste. The clean water is then drawn back into the tank, maintaining clear water and a healthy environment for fish. This biological filtering process is effective and low-maintenance, making it a popular choice for aquariums focusing on biological filtration. Proper setup and maintenance ensure it functions efficiently and supports a thriving aquatic ecosystem.