Thanks to recent advances in technology and lower equipment prices (not to mention Finding Nemo!!), marine fishkeeping is now appealing to more and more fishkeepers. Whether you are ‘upgrading’ from an existing tropical or coldwater set up, or are completely new to all aspects of fishkeeping, keeping marines can sometimes appear to be a daunting prospect. This definitely does not have to be the case, whilst it should still not be undertaken lightly (animal welfare is involved) keeping marine fish and corals has never been easier. The following information has been put together to give an insight into marine fishkeeping and as a resource to ensure that your aquarium is kept looking healthy and vibrant.
There are 2 main ‘types’ of marine aquarium, fish only or a reef aquarium. A fish only aquarium is generally easier to maintain than a reef aquarium as corals are more demanding and are less tolerant of poor water quality. The list of basic equipment is much the same for both types, you will need: Aquarium, protein skimmer, lighting (high output for reef systems, see our marine lighting guide), heating, powerheads for water circulation, filtration. In addition to this list, it may be wise to also include a calcium reactor, uv steriliser etc dependent upon the stock within your aquarium.
The list of equipment above is considered essential, further into this guide we will look at some equipment which, although not essential, can make your life easier and/or your aquarium more spectacular.
When choosing a protein skimmer it is always best, in our experience, to choose one that is rated for a larger aquarium than you intend to keep. For example, if your aquarium is 200 litres, look at a protein skimmer which is rated for at least 300 litres or even 400 and above if you intend to keep more demanding inhabitants.
When choosing a heater a good rule is to allow for 1w of heating per 1 litre of aquarium water. In larger aquariums more than 1 heater may be required and even in smaller aquariums having 2 heaters is a good failsafe to avoid costly losses if one stops working. The heater should be placed in an area with good flow to ensure even heating of the tank.
Good water movement is vital to the health of a marine aquarium. Corals need the movement to bring food and fish will appreciate the exercise. As a 
minimum you should look to turn the tank volume over 10 times per hour, although more would be better and in fact, for a reef aquarium, 15-20+ times per hour is a necessity. This is normally acheived via the use of powerheads such as the Newave or Koralia ranges.
When choosing an aquarium we would suggest that you purchase the largest one that your space/wallet/purse will allow. Marine fish need a larger swimming area than most tropical fish and so it is only right that we keep them in as large a space as we can to ensure they thrive. Ideally there should be at least 9-10 litres of water for every 1 inch of fish in the aquarium. This is just a general rule of thumb, we’re not sure a 6 inch tang would be happy in a 60 litre aquarium (!) so always check the minimum recommended tank size for your wish list of fish, before purchasing the tank if possible.
You also need to consider what type of aquarium you want. Do you want a convenient, all in one set up such as the Red Sea Max? Or would you prefer to choose individual pieces of equipment and design your own system? Both have their merits and which one you choose will ultimately come down to your own personal choice and experience level. Please give us a call if you would like to discuss either option.
So, you’ve bought the aquarium and all the required equipment, now what? Its time to add the water and rockwork. When keeping marine fish and coral it is vital that water quality is very good. We recommend using only reverse osmosis (RO) water for marine systems as this has had all of the contaminants and heavy metals removed. We can provide pre-mixed RO saltwater (we use Red Sea Coral Pro salt), either from our shop, or we can even send you some in reusable containers. We keep our water at a salinity of between 1.022 and 1.025. We would recommend that marine aquariums are kept within this range at all times. The salinity can be checked using either a hydrometer or a refractometer to ensure that it remains within these parameters. A stable salinity is more important than the actual salinity (providing it is within this range. When saltwater evaporates it is only the water that does so, the salt will remain in the aquarium. It is therefore important to top up any evaporation with fresh RO water to ensure a stable salinity.
As for the rockwork, we would recommend using live rock as it forms a major part of the aquariums
filtration system, in fact, live rock, a protein skimmer and good water movement can be all the filtration required in a marine aquarium. The large surface area of live rock is colonised by bacteria which acts as the filtration. You will need approximately 1lb of live rock per gallon (approx 1kg per 10 litres) to ensure adequate filtration. Live rock can be added on top of a base layer of ocean rock if desired. We would advise that the rockwork is added before any sand to ensure that the structure is stable. If you place the rockwork on top of a layer of sand you invite the possibility of a fish or other creature burrowing underneath it and undermining the rock which could cause problems.
Once you’ve got the rockwork, sand and water in the aquarium its time to switch on all of your shiny new equipment!