In order to run a successful marine tank, a few key pieces of hardware are essential. Here’s what you’ll need…
Flow is vital, especially where corals are concerned. Without it, they cannot feed properly and cannot excrete their wastes.
Pumps should be sized according to the tank you have – there’s no extra economy of scale involved in buying too large a pump for your aquarium. Indeed, it may turn out to upset corals and kill them off.
For extra effect, pumps can be connected to a wave-maker device, with alternate flows from one to the other in order to create a back-andforth washing motion.
Absolutely essential. At a bare minimum you want tests for ammonia, nitrite and nitrate, as well as ph. These will tell you whether your tank is safe, and if any adjustments in water management are needed.
Don’t be daunted by test kits – most of them are now very user-friendly, with easy to read instructions. Testing usually involves adding water to a test tube, mixing reagents from one or two bottles and comparing to a colour chart. They are quick to perform and make the difference between success and failure.
Note that in a stony coral reef tank, the level of testing may be so advanced as to require sending samples to a lab for a full analysis. However, for a beginner with a soft coral tank, a good selection of liquid tests will suffice.
Hydrometer or refractometer
Given a choice between a hydrometer and a refractometer (pictured below), the latter is generally more accurate, but both of these devices are designed to measure the amount of salt in your aquarium water.
Marine fish need to be kept within a very narrow range of salinity, which equates to roughly 35g of salt per litre of water. Regular monitoring will allow you to see whether natural evaporation has made the water in your tank especially salty. If it has, you can dilute it as necessary until it’s within the acceptable range again. A hydrometer or refractometer is also a vital piece of equipment when it comes to doing your
regular partial water changes.
The type of heater used in aquaria is called a ‘heaterstat’, which is a heating element encased in a watertight glass tube that has a thermostatic control on it somewhere (usually on the top). Thermostats can be analogue – a simple dial that moves up or down – or they can be digitally controlled. Note that in the world of heaters, you generally get what you pay for, and cheaper models tend to have a higher failure rate.
Aquarium lights will have the correct spectrum for growing corals, and come in two types – fluorescent and light-emitting diode (LED).
Fluorescent lights are the cheaper option to buy initially, but have relatively high running costs due to high wattages and the need to replace light tubes regularly.
LED lights are more expensive, but are far more cost effective in the long run, and most have a lifespan that runs into tens of thousands of hours before they need replacing. LED lights are often controllable in a way that fluorescent lights are not, allowing you to dim and brighten them, change colours and spectrums to suit particular corals, even to the point of replicating natural sunlight (including cloud cover) over the course of a 24-hour cycle.
Most newcomers are baffled by protein skimmers, but they’re actually quite simple devices. Protein skimmers use the power and properties of tiny bubbles (which are extremely sticky to proteins) to collect a froth of protein foam in a cup that sits on top of the skimmer.
The beauty of this is that in removing proteins (which are made up of amino acids), the skimmer is removing lots of the waste that has the potential to turn into ammonia (see page 8 for more on this) before it has had chance to become ammonia. In turn, that puts a great relief on biological filtration, meaning cleaner water and fewer water changes.
Protein skimmers can be fiddly to work with and do require regular adjustments to keep working at their best, but once you get the hang of them, they’re no trickier than any other piece of aquarium equipment.
This can be made of either glass or acrylic. Acrylic is tougher, and a safer bet if you have children or pets in the house, but it does scratch more easily.
Glass aquaria come in either plain or ‘low iron’ (sometimes called optiwhite, or high-clarity) construction. Some tanks have lids, others are open-topped. Note that open-topped tanks increase the risk of fish jumping out (and of things falling in), as well as increase the rate of evaporation, but tanks with a built-in hood may be restrictive on lighting options.
This must be aquarium suitable. Cheap MDF cabinets from generic furniture suppliers may be too weak, and are also prone to swelling and degrading if they get wet. Always use a designated aquarium cabinet where possible. Note that one litre of water weighs 1kg, so a 120-litre tank, combined with glass and rocks, may weigh well over 150kg – far beyond the capacity of your average bedside dressing table.