Getting into the marine aquaria hobby often involves a lot of planning and organization. You might regret it if you blindly run out to the store and buy plenty of equipment, set it up, and then wonder what creatures to buy. That is placing the proverbial cart before the horse. It is ideal to first have a good concept of what you want in a marine aquarium, then you can go out and look for the proper equipment to handle it. Your decisions may have to be changed by information furnished by your pet shop owner or manager, but at least you’ll be able to make the alterations to your ideas accordingly.
When you have decided on the animals you would like to keep (and can keep), the next major decisions are the kind of aquarium tank to buy, its size, its support, and its location.
The ideal tank is the all-glass aquarium. In recent years this type of aquarium has come into its own. Of new tanks bought for either freshwater or marine animals, almost all of them are of the all-glass type. These comprise of four glass sides and a glass bottom secured together with a silicone sealant. At first a lot of aquarists built their own all-glass tanks since the prices for ready-made tanks were often extremely high and it was a comparatively simple matter to put one together. But the prices on manufactured aquarium tanks have gone down so drastically since they first appeared on the market that it no longer pays to take the time or trouble to make your own unless you require a special size or shape.
It is not ideal that you try to modify an old metal-framed tank for marine use. Though it can be done, it is a risky proposition at best, and the potential loss of fish from metal or other poisoning would be greater than the cost of a new all-glass aquarium.
The size of the aquarium tank depends mainly upon what marine animals are to be held. For some fishes and invertebrates a small tank would be sufficient, but for general fishkeeping (or invertebrate keeping) nothing smaller than 25 gallons should be considered. Fifty- to 125-gallon aquaria are more potentially to be chosen by the learned aquarist who knows this larger capacity gives more freedom in choosing the animals to keep and more time to adjust the situation if something goes awry. Once you have mastered the marine methods with a 50-gallon aquarium, you can try the smaller ones for specialty or exotic fishes or invertebrates.