Marine aquariums can be a rewarding and fascinating hobby. If you are interested in pursuing this hobby, our guide to setting up a marine aquarium will help familiarize you with some of the equipment and processes that are involved in selecting and setting up your first marine aquarium. This page also covers some of the tools and accessories that can help make the hobby a little easier and more enjoyable. The information below can help you get started. If you need more detailed information, please be sure to visit your local aquarium store. They will be happy to share their experience with you.
Location | Aquariums | Stands & Canopies | Lighting | Filtration
Water | Substrate | Assembly | Stocking | Maintenance
When deciding on a location for your aquarium, you should find a spot that is not near a window, heater, radiator, or air conditioner vent. It is best to find a location with a stable temperature. You also want to avoid direct sunlight, since this can cause unwanted algae growth in the tank. You will also want to find a spot that will make it easy to maintain the aquarium while still allowing it to be easily seen. Your marine aquarium will be an artistic centerpiece in your home. Make sure you put it in a place where you and your guests will enjoy it. Remember, once you set it up and get it going, you want to avoid moving it. Besides being a real inconvenience, moving the tank will require draining the water and disturbing the animals. This should be avoided as much as possible.
When choosing an aquarium there are a few factors to consider. First you need to choose the material. There are two choices here: glass and acrylic. They both have advantages and disadvantages. Most experts will recommend a glass aquarium, especially for beginners. The size of an aquarium is also important. When it comes to aquariums, larger is always better.
Glass aquariums are usually a better choice for beginners because they tend to be less expensive. They are also resistant to scratching. Also, glass aquariums will maintain their clarity over time. Glass is extremely stable and will not change in color or clarity with age. On the down side, glass aquariums are much heavier than acrylic. Class is brittle and can break under the right conditions. If you choose reputable brand with good, thick glass this is usually not a problem. Glass aquariums are also prone to leakage, since they are constructed from multiple sheets of glass that are glued together. A silicon sealant is used to make the corners waterproof. This seal can fail leading to leakage, but this is rare and again, if you go with a reputable brand this really should not be a problem.
Acrylic aquariums do have some advantages over glass. They can be molded in fewer pieces, leaving fewer seams that could potentially cause leaks. They are also much lighter than glass aquariums. Because it is more pliable, acrylic can be molded into different shapes, providing many more options for someone who may be looking for something a little less traditional. On the down side, acrylic aquariums do scratch easily. Extreme care must be taken when cleaning and placing decorations inside the aquarium such as sharp rocks and coral. Even tiny scratches over time from a cleaning cloth can cause the acrylic to become foggy. Also, acrylic can change color over time, sometimes turning slightly yellow. Acrylic aquariums also tend to cost more than glass.
When it comes to aquariums, size does matter. You should choose the largest tank you can afford and that you have room for. Your fish will grow over time and if you choose to add coral to your tank, the coral will also grow. Soft corals can double in size every few years. It is also better for the fish to give them plenty of room. Tangs, for example, need room to swim. Some species will require a 75 gallon tank as a minimum. Also, larger tanks provide a much more stable environment and are therefore easier to take care of and maintain.
Once you have selected an aquarium, you need to decide what you are going to put it on. It is recommended to solid stand instead of an open frame stand. Solid stands provide much better support and also have the advantage of allowing you to store supplies and equipment out of sight. This is especially important if you will be using an external filtration system that will need to be located underneath the stand. Many people prefer to select a stand that matches the look and style of the aquarium. Many aquarium retailers will sell sets that include a matching aquarium, stand, and canopy. A canopy is a box-shaped lid that goes on top of the aquarium. Canopies usually have a lid that opens on a hinge or a series of doors on the front that open to allow access for cleaning and feeding. The aquarium lights can be mounted inside the canopy to provide a clean, finished look for the system. A new trend in the aquarium hobby is to go "topless". The lights can be hung from the ceiling to create an interesting effect and allow full access to the tank for cleaning and maintenance. Keeping the lights on the outside of the aquarium can also help keep the water cooler. It all comes down to personal preference. Using a canopy will hide the glare of the lights from view and generally provides a more pleasing and finished look for the system. However, depending on the type of lights you are using, keeping them inside a canopy could raise the temperature of the water, requiring the use of a chilling unit in some cases.
Providing the right kind of light for the aquarium is important for several reasons. First, saltwater fish can be very colorful and expensive and you will want to make sure to show off your investment. Also, providing a regular cycle of light each day is important for the wellbeing of the animals in your tank. Lights should be set up with timers to provide a consistent cycle of day and night. Experts recommend 8 to 10 hours of light per day. Keeping a regular cycle will help to reduce stress which can help to minimize the chances of disease. If you are planning to keep coral in your aquarium, lighting will be even more important. Most corals use light to make food and many species will have specific lighting requirements and will die if not provided with proper lighting. There are several options available for lighting your aquarium.
Fluorescent lights provide one of the easiest ways to light an aquarium. They are inexpensive and are available in a variety of sizes and colors. They are also the fairly energy efficient. Fixtures for fluorescent lights care available that can be mounted directly to the tank if you choose to go topless. Other fixtures are available that can be mounted inside a canopy. Fluorescent lighting is good for fish-only tanks. They can also be used with some soft corals as long as the proper color and intensity is provided. Fluorescent bulbs must be replaced because as they age, the wavelength and intensity of their light decreases. Most experts recommend replacing fluorescent light every 12 to 18 months.
Metal Halide Lights
Metal halide lights are high intensity lighting systems that are popular with more advanced aquarium hobbyists. The provide an intense light that approaches that of natural daylight. This is important if you plan to keep a lot of coral in your tank, particularly with the hard corals. These corals contain a symbiotic green algae called zooxanthellae. This algae uses sunlight to make food for the coral. If this algae dies, the coral will eventually die. The light from metal halide bulbs can penetrate much deeper into the water than fluorescent, making them a better choice for large or deep aquariums. The disadvantage of metal halide lights is that they are expensive to install and they use a lot of electricity. They also burn hot and can raise the temperature of the water if kept inside a canopy. Some people use a combination of metal halide and fluorescent to provide the right mixture of light intensity and color.
Light Emitting Diodes (LED) lights are the new kid on the block. They have just been introduced over the last few years and have just recently become a viable alternative to fluorescent and metal halide. They are currently the most expensive option to install, but they could end up saving you money over time. They are extremely energy efficient and they burn much cooler that other types of lights. They are also very compact and can be mounted in a canopy or directly above a topless tank. They are also bright enough to be used with all types of corals. LED lights come in a variety of colors, and many of the newer units are programmable. This means you can set them to change colors and provide a variety of effects. Most can be set up to go on and off at certain time without the need for an external timer. Some can even be programmed to turn on and off gradually to simulate sunrise and sunset. This provides a much more natural environment for the animals and can help to reduce the stress of light suddenly turning on and off. As prices come down over the next few years, LED lighting has the potential to replace fluorescent and metal halide as the preferred lighting system for all types of aquariums.
Now that you have chosen a tank, stand, and lighting system, you need to consider filtration. There are several methods for filtering the water. The best methods use what is known as biological filtration, in which beneficial bacteria remove toxins from the water. Fish give off a toxin called ammonia. The bacteria in the filter convert the toxic ammonia into nitrite, which is slightly less toxic. A second type of bacteria converts the nitrite into nitrate, which is even less toxic. As nitrate builds up, it can be removed by monthly water changes. This is what is known in the hobby as the nitrogen cycle.
The first thing you must decide is whether or not you are going to use a sump. A sump is a small tank or container that sits underneath the aquarium, usually inside the aquarium stand. Sumps are available with and without filtration. Using a sump together with live sand and live rock is the preferred method for most marine aquarium hobbyists, and it will provide you with much better success in the long run. Sumps provide a convenient place to perform maintenance and to add additional filtration such as a protein skimmer or nitrate reactor. It also adds additional water to the system which can help to make it more stable. Additionally, water flowing down into the sump and back up into the aquarium help to keep the water well oxygenated. The only down side to a sump is that it has to be properly plumbed. But PVC piping is extremely easy to work with and anyone should be able to do it with a little practice. If you choose not to use a sump, there are other filtration methods available.
The popularity of undergravel filters has been declining over the years as new methods have become available. Undergravel filters consist of a plate that pulls water down through a substrate, usually gravel, and the recirculates it back into the tank. The gravel provides a medium for the nitrifying bacteria to grow. They are usually powered by an air pump or air stone. Undergravel filters are best used in smaller tanks under 55 gallons. They can work well for fish-only tanks but require frequent maintenance to keep the gravel clean. They are not suitable for tanks with a lot of fish since their filtration ability is limited. Use of these filters does require a break-in period known as cycling before fish can be added to the aquarium.
Wet/Dry Trickle Filters
Wet/dry trickle filters are a step up from the undergravel filters. The attach to the back of the aquarium and work by pumping water out of the tank and into a container with some type of filter media. Many of them use a wheel that rotates when the water passes over it. The wheel provides a place for the nitrifying bacteria to grow. These filters are only suitable for small aquariums under 55 gallons. They can work well for fish-only systems but they do require a lot of maintenance to ensure that the filters are kept clean. Also, the systems with the wheels are notorious for getting clogged. If the wheel stops turning, it can dry out an you can lose most of your beneficial bacteria which can significantly reduce the system's ability to effectively filter the water. Use of these filters does require a break-in period known as cycling before fish can be added to the aquarium.
Canister filters consist of a container that sits below the aquarium. They usually have a built-in pump that draws water down out of the tank, through the filter, and then pumps it back up into the aquarium. They use a combination of mechanical and biological filtration. The mechanical filtration is provided by a series of filter pads. Biological filtration is usually provided by a medium consisting of small plastic or ceramic pellets which provide a medium for the nitrifying bacteria to grow. Canister filters are a better choice than undergravel or trickle filters. They can be used successfully with larger aquariums. However, they do require regular maintenance and can be challenging to disassemble and clean. Failing to clean the filter pads on a regular basis can actually make the water quality worse as detritus and other gunk trapped in the pads can start to introduce toxins into the water. Use of these filters does require a break-in period known as cycling before fish can be added to the aquarium.
Live Rock/Live Sand
By far the most preferred method of filtration for marine aquariums is through the use of live sand and/or live rock. Live sand consists of sand that has been cultured in the ocean and contains beneficial bacteria that is capable of filtering the water. Likewise, live rock consists of rock that has been cultured in the ocean and contains the same filtering bacteria. Using live sand for filtration is known as the Jaubert method while using live rock is known as the Berlin method. In the Jaubert method, a bed of live sand about 4 inches deep is used to provide biological filtration. In the Berlin method, live rock serves as a platform for the bacteria to provide filtration. It also has the added benefit of providing a natural and realistic setting for both fish and coral. For a Berlin system the general rule of thumb is to add 1.5 pounds of live rock for every gallon of water in the aquarium. Many serious aquarium hobbyists prefer to use both live rock and live sand. Both can be obtained from your local aquarium retailer. One added benefit to both of these systems is that they usually do not require a lengthy cycle time, since the nitrifying bacteria is already present in the system. With other filtration systems, a cycling period of up to a month is required to allow time for the bacteria to grow. Both of these systems are typically used in combination with a sump located below the tank. Water falls down into the sump through a hole in the aquarium and is pumped back up into the tank by a mechanical pump. Using a protein skimmer provides additional filtration by removing organic waste from the water. Protein skimmers are usually placed in the sump.
For a marine aquarium, tap water is not recommended. Most city water supplies contain a number of chemicals that are toxic to fish and invertebrates. Chlorine, chloramine, fluoride, nitrate, phosphate, and copper are all found in tap water and are poisonous to marine animals. The chlorine and chloramine can be removed using chemicals, but the other toxins will remain in the water and will build up in your aquarium over time. By far the best type of water to use is Reverse Osmosis De-Ionized water, often referred to simply as RO water. You can usually find RO water at your local aquarium store and sometimes at the grocery store. If you can't get RO water, distilled water will suffice. If you are planning to be serious about the hobby, you may want to consider investing in an RO/DI filter unit. This consists of a number of a reverse osmosis filter membrane and a number of filter canisters including a deionization (DI) filter. RO/DI units can be purchased for as little as $150.00 and will be much more convenient that lugging home buckets or bottles of water from the store. You will want to purchase a TDS (Total Dissolved Solids) meter to check your water quality so you will need to know when to change the filters. Some RO/DI units are available with TDS meters build in. If you have a large aquarium, consider purchasing a sturdy plastic trash can with wheels to hold your water. You can mix the salt and then wheel it right up to you aquarium to do the water change. Rubbermaid makes a sturdy can called the Brute which is perfect for the job. They also sell heavy duty wheels that snap right on to the bottom of the can.
Substrate is the material you put on the bottom of the aquarium. For a marine aquarium it is usually sand or crushed coral unless you are using an undergravel filter. The best type of substrate for a marine aquarium is one that is high in calcium. Crushed coral and fine sand known as aragonite are both good choices. Crushed coral is much more coarse and will give the system a different look. It really comes down to personal preference. We have been using live sand and have had nothing but good luck with it. Live sand is cultured in the ocean and contains naturally-occurring bacteria and other critters that help to filter the water and keep it clean. You will need to decide how deep you want the substrate layer to be. Most experts recommend between 2 and 4 inches. If you are using live sand then more is better and 4 inches is recommended. There is a new trend in the hobby to go "bottomless". Some people fear that the substrate can become fouled over the time and can eventually harm the tank. The prefer to use no substrate at all. There seems to be no strong evidence that this makes any difference. So again, it comes down to personal preference. We have been using 4 inches of live sand an our tank is over 10 years old with fish and live coral. As long as you use RO/DI water, monitor your water quality, install a good protein skimmer, and do you monthly water changes, you really shouldn't have any problems with sand or crushed coral.
Now that you have the aquarium, stand, lights, and filter, set everything up as directed. If you are using live sand you can add it directly to the tank right out of the bag. Otherwise, crushed coral and aragonite sand will have to be thoroughly cleaned before adding to the tank. Wash it in a bucket with clean water until the water runs clear. Mix your saltwater using a large bucket or clean plastic garbage can. Check the specific gravity using an appropriate hydrometer from you local pet or aquarium store. You will want it to read 1.026 with the water temperature around 78 degrees F (26 degrees C). Add the substrate to the tank and then slowly start to add your water. Stop occasionally to check for leaks. There is nothing worse than filling a 90 gallon aquarium full of RO/DI water and then finding a leak and having to drain it again. Only fill the tank about 3/4 of the way to allow room for your decorations.
If you are using live rock you can go ahead and add it now. Stack it and arrange it to suit your taste. Many hobbyists prefer to make tall formations in the middle of the tank rather than stacking it up against the back glass. This also helps to provide better water circulation and can prevent the buildup of detritus in what are known as "dead zones". If you are not using live rock, you can find a variety of decorating ideas at your local aquarium retailer or pet shop. Natural rock and dried coral can be used. Several companies also sell artificial coral, some of which looks nearly as good as the real thing. Just make sure anything you put in the aquarium is clean and is approved for use in a saltwater aquarium. Once you are finished decorating, top off the water and turn on the pump. Let the system run for a day or two to clear the water. If you are using live sand and/or live rock, you may be able to add fish after only a couple of days. Check with the store where you bought your live rock and make sure it has been properly cured. Test the water and make sure the levels of ammonia, nitrate, and nitrite are staying at zero. It is always best to add just one or two animals to start and monitor the water quality. Give the system time to adjust before adding more. Monitor you water quality closely to avoid any problems. Most aquarium retailers will offer to test your water for you.
If you are not using live sand/love rock the you will have to cycle the tank before you can add any animals. One easy way to cycle the tank is to buy one or two uncooked shrimp from your local supermarket and throw them into the tank. As they rot, the bacteria will begin to grow. Some aquarium retailers sell bacteria additives that can be added to the water to speed the cycling process. Test your water daily. You will see ammonia levels rise first over 7 to 10 days. Next, the ammonia will drop suddenly and nitrites will begin to rise. After about a week the nitrites will drop and nitrates will start to rise. Once ammonia and nitrite read zero in your water test, it is safe to add fish. Be sure to go slow and only add one or two at a time. Watch your water quality and give the system time to adjust after each new addition. Patience is the key. If you add too many animals too fast, you could get an ammonia spike which could kill your fish.
Once your aquarium system has cycled and the water tests OK, it is time to add some life. You can purchase your animals from a local aquarium store or purchase them online. Online retailers offer attractive prices and fast shipping. The only problem is that you can't see exactly what you are getting. If you picky about the coloration and size of the fish you want in your tank, you may want to get them from a local aquarium retailer. You can invertebrates such as crabs and snails online if you can find better prices.
When selecting animals for purchase, examine them closely to make sure they look healthy. Make sure they do not have any marks or white spots on them. Make sure their eyes are clear and not white. Ask someone at the store to offer them some food so you can make sure they are eating. Do not purchase an animal that refuses food at the store. When purchasing coral, select a specimen with fully open polyps. Do not purchase any coral with dead spots on it. Most aquarium retailers offer a guarantee of one or more days in case the animal dies when you get it home.
Once you get the animals home, they must be acclimated before they are introduced into the tank. The best way to acclimate animals is to put them into a clean bucket along with the water that came with them. Gradually add water from the aquarium to the bucket using a measuring cup or by using some plastic tubing. Start a siphon in the tubing and tie a knot in it so that it drips slowly into the bucket. You want to gradually add about three times the amount of water that was originally in the bucket over a period of 15 to 30 minutes. Once the acclimation process is complete you can place the animals in the tank using a net. Be careful not to get fish fins and gills caught in the net. If you have invertebrates in your aquarium, DO NOT put any of the water that came with the animals in your tank. Many aquarium stores put copper in their water to help prevent diseases in their fish. Copper is extremely toxic to invertebrates and will kill shrimps, crabs, and coral.
It may take a few days for the new animals to adjust to their new surroundings. Feeding the existing fish in the tank before adding new ones can help prevent aggressive behavior. If you do notice some animals being aggressive to the new ones, turning the lights off for the night may help. Monitor your new animals closely for the first few days and seek help from your local aquarium store if you see any problems.
Now that you have the aquarium up and running it is time to start thinking about maintenance. The three most important parts of maintenance are water replacement, water changes, and water testing.
As water evaporates from the system, you will need to add new RO/DI or distilled water to replace it. When the water evaporates, the salt stays behind. Therefore you will add unsalted water to replace the evaporated water. If you have a sump you may want to mark a line on the outside and strive to keep the water level at that line. It is recommended to add water every day rather than every few days. This keeps the specific gravity of the water consistent and avoids large fluctuations which can stress the animals in the tank.
Nitrate is the final result of the nitrogen cycle. It must be removed by changing the water. For a small tank, it is recommended that you change out about 10% of the water every two weeks. Since larger tanks are more stable, they can take a 20% water change once a month. Turn off the pump and drain the water using a siphon hose. Purchase a good salt mix from your local aquarium retailer or pet store. Mix new saltwater to the same specific gravity and pH as the water in the tank. Make sure the temperature of the new water is as close as possible to the temperature in the tank. Pour or pump the new water into the tank and turn the pump back on. Doing this once a month serves two purposes. If keeps the nitrate levels down and it replenishes important elements in the water.
It is important to test your aquarium water on a regular basis. Over time, the system should become more stable. However, occasional problems can still pop up. Buildup of waste and detritus as well as dead animals can cause ammonia spikes which are serious life-threatening problems for the livestock in your tank. A build-up of nitrate and phosphate can cause uncontrolled algae growth. Once established, some of this algae can be difficult to control. If you have invertebrates and/or corals in your aquarium, it is necessary to keep track of calcium and alkalinity levels. A drop in calcium or fluctuation in alkalinity can kill invertebrates such as shrimp, crabs, and coral. If you have a fish-only aquarium you will need to check ammonia, nitrite, nitrate, and pH at least once per week. If you have invertebrates and/or coral you will also need to check calcium and alkalinity. You should also check phosphate levels to keep algae under control. Most local aquarium retailers will offer to check your water for you. However, you should still keep test kits on hand for emergencies. This will allow you to take immediate action if a problem occurs when the local aquarium store is closed.
The optimal temperature for a marine aquarium is around 78 degrees F (26 degrees C) . Anything above 82 is definitely too hot, and anything below 76 is too cold. It is a good idea to purchase a thermometer for the aquarium. Many low-cost digital models are available that attach to the side of the tank. They have a sensor probe that is placed inside the aquarium to monitor the temperature. Some of them even have an alarm that can be programmed to go off if the temperature gets too high or too low. During winter months you may need to use a heater to keep the water warm enough. The best heaters are fully submersible. Once properly adjusted, they will keep the water at a consistent temperature. Aquarium heaters com in different sizes. Make sure you get a one that is made for the size of your aquarium. If the heater is too small, it will not maintain a constant temperature. With heaters it is better to get one too big rather than too small. During the summer, if you find the water temperature consistently rising above 80 degrees F (27 degrees C), you may want to consider purchasing a chiller. A chiller is a small refrigeration unit that is hooked up to the aquarium to cool the water. They are typically up in-line with the water return. They can be programmed to maintain the temperature at a desired level. Some chillers even have a place to plug in a heater so that you can leave both units hooked up all year.
Every day you should check the water level and add fresh RO/DI or distilled water to replace evaporated water. Also, check the temperature and make sure it is steady. Add a heater or chiller if necessary during periods of extreme cold or heat. Check any filters to see if they need to be cleaned. If you have a protein skimmer, check it and empty the cup if it is full. Check fish to make sure there are no signs of stress or disease. Feed the animals and remove any uneaten food as necessary.
Once a week you need to check the water quality. For fish-only systems, check ammonia, nitrate, nitrite, and pH. If you have invertebrates and/or coral in the tank you will also need to check alkalinity and calcium levels. Scrape any algae from the glass or acrylic using a cleaning pad approved for use on the type of aquarium you have. Be extremely careful with acrylic tanks as they scratch easily. Also, check filters for clogs and clean them if necessary.
Every two weeks you should do a water change. Remove 10% of the water from the tank and replace it with freshly-mixed saltwater with the same specific gravity and pH as the water in the tank. You can also gently vacuum the substrate as you siphon the water for removal. Clean any mechanical filtration media if you have it. Clean the aquarium glass and also clean any salt buildup, calcium deposits, etc. to keep the aquarium looking nice. Check the lights and electrical connections to make sure everything is clean and replace lights as needed.
If you are using fluorescent bulbs you will need to replace them every 12 to 18 months. As these lights age, their intensity and wavelength will change. This may cause more algae to grow in the aquarium and some of your corals may suffer. Also, it is a good idea to remove any powerheads in the tank and give them a good cleaning. Scrub away algae with a soft brush. If they are covered with calcium deposits or coralline algae, you can soak them in vinegar overnight to soften it up. IT is also a good idea once a year to remove your aquarium pump and give it a thorough cleaning.
Glossary of Terms | Aquarium FAQ | Aquarium Setup | Aquarium Equipment
Diseases & Pests | Clubs & Organizations | Public Aquariums | Aquarium Software
Aquarium Photo Gallery | Aquarium Suppliers | Aquarium Resources | My Sea