A fish tank's life support system is an essential part of keeping a healthy and thriving aquarium. It consists of several components that work together to provide the optimal environment for your fish to live in. The most important components of a life support system include filtration, aeration, temperature control, water quality testing, and lighting. Filtration is one of the most important aspects of any successful aquarium setup because it helps keep the water clean by removing organic waste such as uneaten food and decaying plant matter from the water column. Aeration ensures that oxygen levels are kept high enough to sustain aquatic life while also maintaining proper pH levels in the tank. Temperature control is critical for certain species so they can survive in their natural habitats; this can be achieved through heating or cooling devices depending on what type of fish you have. Water quality testing should be done regularly to make sure all parameters remain within acceptable limits so that your livestock remains healthy and happy. Finally, adequate lighting will not only help promote photosynthesis but also allow you to observe your fishes' behaviors more closely which can tell you if something isn't quite right with them or their environment!