Marine fish are some of the most beautiful fish available, and their interesting behavior, bright colors, and wide range of body shapes and sizes lend interest and color to the home aquarium.
Their care needing’s are different to those of freshwater fish however, and their tolerance for variations in such parameters as temperature and pH is less than that of freshwater fish. The ocean itself is remarkably stable, with very little fluctuation on a daily or even annual basis, and for that reason it is very important to maintain a stable environment for any Marine fish held in an aquarium. It is important to spend time in establishing good tank environment well before adding any fish and corals, and to monitor the conditions in the tank regularly once it is set.
Most of the people achieve this, with the establishment of a regular inspection routine and good maintenance habits. Below you will find a guide to establishing and maintaining your own Marine tank. This guide will act as a basic introduction to “How to set up a saltwater fish tank and maintain”, but is by no means comprehensive. For more information, speak to our Support Staff.
Which system is right for you? “Fish Only” or as a “Reef System”
There are essentially 2 different ways to set up a Marine Aquarium – as either “Fish Only” or as a “Reef System”. Reef systems contain Coral, Live Rock, Crabs and / or Shrimp in addition to Fish. Below are the recommended water parameters for these 2 different systems:
Water Parameters (Fish Only System)
Temperature 24ºC – 27 ºC
SG 1.020 – 1.024 ppt
pH 8.0 – 8.4
Ammonia (NH3) zero
Nitrite (NO2-) zero
Nitrate (NO3-) < 20 mg/L
Phosphate < 0.02 mg/L
Alkalinity 125 – 200 mg/L
Copper 0 – 0.3 mg/L
Water Parameters (Reef system, fish/invertebrates )
Temperature 24ºC – 27 ºC
SG 1.023 – 1.026 ppt
pH 8.0 – 8.4
Ammonia (NH3) zero
Nitrite (NO2-) zero
Nitrate (NO3-) < 10 mg/L
Phosphate < 0.02 mg/L
Alkalinity 125 – 200 mg/L
Calcium 400 – 475 mg/L
Copper zero (toxic to invertebrates)
Checklist for setting up your Marine Tank
Your Aquarium Retailer will be able to provide you with all of the items below. Ask them about “All in One Systems” too, which are now available in arexotics.com. These have been packaged by some of the major suppliers to contain the majority of the required components, and require less time and effort when assembling.
- Tank
The tank should be as large as possible for the space you have provided. The larger the tank, the more stable the water conditions and, as previously mentioned, it is very important to keep the water conditions stable for these fish. Also ensure that the tank is the appropriate size for the fish you will be housing (e.g. active, mobile swimmers such as Tangs require a larger tank than Clownfish.) The Aquarium Industries website contains Care Sheets for most Marine species, and you will find out more about the required tank size by downloading these Care Sheets. - Filtration
Under gravel filters are generally not recommended, as they are easily clogged by sand. Due to their size, they are also usually not effective enough to cope with the large amount of water required in marine systems.
Hang on back filters provide gentle water movement and provide good bio-filtration but not much mechanical filtration. They will suit a small tank with one Clownfish.
Canister filters provide excellent mechanical and biological filtration, and can be used for chemical filtration. They are usually used in conjunction with other filter components.
Trickle systems are excellent for fish only systems, but they leave high levels of nitrate which is undesirable for invertebrates (live rock can be used instead of bio balls for reef tanks). Trickle systems can be used in conjunction with other filtration methods to help reduce and eliminate nitrates.
Protein skimmers are excellent at removing nitrogenous and organic compounds before they need to be broken down by the biological filter. This is essential for Reef Systems.
Live rock in conjunction with good water movement provided by powerheads creates excellent nitrification and denitrification because of the large surface area of the rock. down the organism.
UV sterilizers eliminate pathogens and suspended organic matter by exposing the water (and its micro inhabitants) to Ultra violet light which destroys the cell walls and breaks down the organism.
Deep sand beds, refugium’s, fluidized sand filters and algae turf scrubbers are other methods of filtration used for marine systems.
- Temperature
Is controlled by heaters and/or chillers which are either installed within the tank or run separately from the sump. - Substrate
It is best to use a calcareous substrate such as crushed coral or aragonite. These substances will help buffer the pH. The size of the substrate should not be so small as to get sucked into any filtration, but not large enough to pose problems to sand sifting fish such as gobies. The average size used is around 1 – 3mm. - Decorations
Should be made up of substances that will not negatively alter the water chemistry. Dead coral, lava rock and coral rubble are all suitable choices. Live rock will also perform biological filtration (see “Filtration”). Only cured live rock should be added to an established tank, as premium live rock will have flora and fauna that are still dying off and which will create ammonia spikes. Premium live rock may also introduce unwanted animals into your established tank. - Test Kits
Good quality test kits are essential to test for the above-mentioned parameters. Electronic meters are available, but are expensive. To measure the specific gravity of the water, you need a hydrometer or refractometer. There are 2 types of hydrometers: the glass type that floats (and usually measures temperature as well), and the plastic kind with a floating arm. Refractometers are more accurate than hydrometers. - Water
Marine tanks require the addition of salt, to mimic the condition of sea water. Use good quality marine salt that contains no nitrates or phosphates and has all of the trace elements needed for marine organisms. Rock salt or conditioning salts cannot ever be used as a substitute. Natural sea water can be used, as long as it is obtained from an unpolluted source. - Lighting
For a fish only tank lighting is not critical. Reef setups require specific lighting, such as metal halide, high outputT5, actinic lighting and/or LED lighting.
Please check for the next article Establishing a Marine Tank
