Saltwater aquariums can be grouped into three basic types – fish-only aquariums, fish-only-with-live-rock aquariums, and reef aquariums. The following article will describe the differences between the three and the benefits of each.
FISH-ONLY MARINE AQUARIUMS
Fish-only aquariums, as their name implies, are designed to house and showcase marine fish. Since the fish are the centre of attention, FO aquariums are sparsely decorated, often with coral skeletons or coral replicas. Like any aquarium setup, maintaining proper water parameters and employing efficient filtration is key. The availability of beautiful and hardy marine fish such as damselfish, yellow tangs, and captive-bred species adds to the success of FO aquariums. The fish-only aquarium is a great setup for the dedicated beginner interested in marine aquariums. This saltwater setup allows novice hobbyists to become familiar with equipment, water parameters, fish, and the maintenance of marine aquariums without the added complications of a FOWLR or reef tank.
FOWLR AQUARIUMS (Fish-only-with-live-rock)
Fish-only-with-live-rock (FOWLR) aquariums are the stepping stone between FO aquariums and reef aquariums. While marine fish are still the focus of FOWLR aquariums, basic elements of the reef aquarium are introduced – most notably, live rock. Live rock is fragmented pieces of biologically-active calcium-based “rock” naturally colonized by a variety of marine life including invertebrates, sponges, and beneficial nitrifying bacteria. Live rock provides excellent supplemental filtration and helps maintain stable water parameters. Additionally, live rock adds a new dimension to the aesthetics and care to the basic marine aquarium. Special considerations for FOWLR setups include proper curing or acclimation of reef rock, additional light or supplements to cultivate desirable coralline algae, and the restriction of many medications that harm beneficial life found in reef rock.
REEF MARINE AQUARIUMS
Considered by many to be the pinnacle of fish keeping, the reef tank is the most challenging and expensive of the marine aquariums. Reef aquariums come in different forms, with some being focused on specific types of coral, such as SPS corals, while others are designed to replicate a natural reef, containing a variety of fish, corals and invertebrates. Since marine invertebrates are very sensitive to water conditions, water parameters must be monitored on a regular basis to maintain pristine conditions. Also, many corals are photosynthetic and require proper lighting to survive. The inhabitants of reef aquariums require special attention, so it is crucial to research lighting, water movement, supplementation, and other requirements before setting up a reef tank.