55 gallons is perhaps the most popular aquarium size, particularly among beginners. These tanks are economical. They are "large" aquariums with a thrilling length of four feet. 55-gallon aquariums also offer seemingly endless possibilities. There are so many different fishes that would work in a 55-gallon aquarium that it opens the door to so many fishes and new experiences within the world of cichlids. Below you will find some suggested stocking combinations, but by no means is this list exhaustive.
The following combinations are many and varied; therefore, it
does not make sense to comment categorically here on substrate
or decorations. Please research each setup's specific requirements.
Items to consider are diet, substrate, plants, rocks, and caves.
A reliable heater, preferably 200W, is always an important consideration.
There are many effective methods for filtering a 55-gallon aquarium. Wet/Dry filters, such as the Tidepool I, are excellent filters. They are not as popular as other methods however due to the extra work required to get them plumbed and fitted to the aquarium. One of the most popular and effective methods for filtration is to use a canister filter in addition to either a Hang-On-Back (HOB) filter or a submersible sponge filter. Suggested canister filters include Eheim 2026, Eheim 2213, Fluval 303, Magnum 350, and Filstar XP2. Companion HOB filters include Emperor 400 and Aquaclear 500. There are many submersible pumps which could be attached to a sponge. These can be used to create additional water movement and extra polishing. Each of these methods would benefit from at least one airstone. 
