How can I set up a beautiful marine aquarium in my home without too much effort? A good question! There are several ways to achieve this, and one of those ways is discussed in this article. Based on experience, the system discussed here is one of the simplest methods to maintain a beautiful marine aquarium. Keeping a marine aquarium is more expensive than a freshwater aquarium. By following the tips and advice in this article, many unnecessary costs can be avoided. Especially the startup costs (purchase of the system, rock, and animals) will be high, but the "operational costs" can be significantly reduced with the choice of a good system. This guide focuses on a “combined tank,” meaning one with both fish and invertebrates. Many of the tips and advice also apply to other systems, such as aquariums with only fish.
Good preparation saves a lot of work. After all, you want a stable and healthy tank with minimal difficulties. Consider the following points carefully before purchasing anything:
Tank Size: In a deeper tank, you can more easily create a nice depth effect. As a minimum, we recommend a tank of at least 250-300 liters. If you can control the fish population well, you might opt for a smaller system.
The most practical choice is a tank with an overflow. Thanks to this overflow, you don’t have to worry about potential problems with power outages and similar issues. Furthermore, it has been shown that most waste accumulates at the water surface. By filtering the surface water, the efficiency of the filtration system is optimal.
Choice of Livestock: Try to think in advance about what you want to keep. Many stores offer animals that absolutely cannot be kept together in a tank, or animals that are even completely unsuitable. To avoid impulse purchases, it’s helpful to make a plan regarding the stocking of the system.
Equipment: Good equipment (filter system, lighting, pumps) is not cheap. However, don’t skimp on this! Starting with poor equipment leads to poor results, which means either buying better equipment later or giving up the hobby. Both are a waste!
Tank Placement: Generally, the most attractive option is to place the tank in a slightly darker part of the room. This way, the aquarium stands out more.
We recommend a combined filtration system. This means: good quality live rock in the aquarium itself and a good protein skimmer. Optionally, a drip filter can also be used. The live rock is full of the right organisms to "seed" the system with the appropriate life. Some of the biological breakdown of waste also occurs in the rock. The protein skimmer removes waste before it is broken down. Additionally, it provides extra oxygen. This reduces the load on the water, thus maintaining better water quality. The protein skimmer is essentially the heart of the filtration system. Normally, the protein skimmer is placed in a tank beneath the main aquarium. This tank is also known as a “sump.” It is also possible to connect a drip filter to this sump. This filter provides additional filtration and extra gas exchange: more oxygen and removal of ammonia, further relieving the water.
In addition to these filtration systems, other methods of filtration can also be applied. Here are a few of them. Activated Carbon Filtration is an important one: activated carbon removes color, odor, and toxins from the water. It is highly recommended to regularly filter the water through carbon. Phosphate-absorbing pellets essentially suck the phosphate out of the water. By keeping the phosphate level as low as possible, we prevent a lot of trouble with algae growth. When purchasing these pellets, make sure to get iron-containing phosphate-absorbing pellets. These pellets are dark brown to almost black in color and work excellently. You need to force the water through them; letting the water passively flow through a bag of these pellets is wasteful. Before the water reaches the actual filter, it is useful to filter it through filter wool. By frequently replacing this wool, we remove a lot of debris!
It is important to perform regular water changes. By doing so, we remove some of the waste products, and useful substances such as calcium and carbonate (KH) are added. In many aquariums, it is quite possible to maintain calcium and KH levels with water changes. A bi-weekly change of 10-15% is usually sufficient. The new water is prepared using temperature-adjusted osmosis water. The correct amount of salt is dissolved in it. Before using the water, it must be circulated with a pump for at least 24 hours. Check before the change that the temperature and salt concentration are the same as those in the aquarium. When changing the water, it is wise to use a siphon to remove any debris from the substrate.
This includes ozone generators, UV sterilizers, oxygen reactors, calcium reactors, etc. Most of this equipment is unnecessary under normal conditions. Ozone and UV are especially useful in an aquarium with primarily fish or if one wants to keep fish that are very sensitive to parasites. However, the calcium reactor is highly recommended. When purchasing auxiliary equipment, pay attention to the quality of the materials used. Not all materials are suitable for use in seawater. Safe materials include: glass, nylon, most hard plastics, Teflon, and acrylic. Soft plastics should be used as little as possible.
Lighting remains a complex topic. Most invertebrates need light to survive. Their tissues contain single-celled algae, called zooxanthellae. These zooxanthellae use light to create nutrients. Their host, such as a coral, lives off these nutrients. Zooxanthellae, like all plants and algae, need light to live. The more light, the better. For larger and deeper aquariums, HQI lighting is generally the best option. Apart from the amount of light, the color of the light is also important. Blue-white light, similar to what we find in the oceans, is the best choice. Other light colors can lead to algae problems and dying invertebrates. Another advantage of HQI lighting is the beautiful shimmer in the water and the fact that fewer cables and wires are needed to achieve good lighting. Additionally, various colored stony corals are easier to maintain their color under bright HQI light. Often, a combination of HQI and T5 or fluorescent lighting is chosen. It is also possible to maintain a beautiful aquarium without HQI!
HQI Lighting
Advantages: Provides a beautiful shimmer in the water, creates a nice shadow effect, can illuminate deep aquariums, fewer cables, many light colors available. Disadvantages: The lamps need to be hung high, so the hood must be high, or an open tank must be chosen. The latter is not necessarily a disadvantage. Another disadvantage: the cost.
Fluorescent Lighting
Advantages: Many colors available, not expensive. Disadvantages: It is difficult to provide a tank with intense light, many stony corals do better under more light.
T5 Lighting
Advantages: Many colors available, it is possible to achieve sufficient light for stony corals with a low hood. Disadvantages: The shadow effect is not as nice as with HQI, more expensive than fluorescent lighting.
LED Lighting
Nowadays, LED is indispensable in the marine aquarium world. Besides being more energy-efficient than the previously mentioned lighting sources, it is also very flexible for obtaining the right color. It can be set up, programmed, often controlled via WiFi, and operated with a phone. Corals grow very well under this type of lighting, and colors can be enhanced with LED.
26°C is the optimal temperature for a tropical marine aquarium. Temperatures above 29°C can lead to oxygen deprivation and the expulsion of zooxanthellae by the invertebrates. The correct temperature is easily maintained with a good heater placed in the filter. It is best to place the heater in the filter to prevent it from being damaged by animals or falling rocks. Additionally, all the water flows past the heater this way, ensuring even heating of the water.
In many cases, the tank gets warmer rather than colder. Using a regular fan to blow over the water surface can make a significant difference. The best solution is to use a chiller. This chiller can be set to the correct temperature. If the water becomes too warm, the chiller will cool it down to the proper temperature. Alternatively, air conditioning is often mentioned, but this is not a good alternative. While you benefit from it too, you would need approximately TEN TIMES the power of a chiller to keep a tank cool!
Another important aspect is water movement. The current on coral reefs is often very strong, which is hardly replicable in an aquarium. A flow rate of 10 times the tank volume per hour is a minimum. For a 300-liter tank, this means you need at least 3000 liters per hour of pump capacity. Normally, the capacity of the pump that returns the water to the tank, the so-called main pump, is not included in this calculation. In some cases, it is even advisable to increase the capacity to 40 times (yes, forty!) the tank volume per hour. It may sound unbelievable, but most fish have no trouble swimming normally even with such a massive flow. Besides being beneficial for various corals, strong flow has the advantage of preventing debris from settling. By keeping the debris in motion, it can be more easily removed by the filter. Try to arrange the setup so that there are as few flow-free zones as possible.
The simplest method is to prepare the seawater using synthetic sea salt and freshwater. It is best to use osmosis water, which is made using a reverse osmosis unit. By using this water, you prevent poisoning and unnecessary algae problems. The salinity should be between 33 and 35 ‰. This level can be easily determined with a hydrometer (“salt meter” or “float”). A density between 1.022 and 1.024 (at 25°C) corresponds to a salinity between 33 and 35 ‰. Natural seawater can also be used, but we advise against it. You run the risk of introducing undesirable organisms that can spoil your entire tank. Especially in summer, you are at a high risk of introducing troublesome algae. People who claim that natural seawater is unusable due to its composition are wrong: the animals come from the sea, and what could be in the sea? To eliminate unnecessary risks, we recommend using synthetic sea salt with osmosis water. To measure the salinity, we advise using a high-quality salt meter. It is important to measure the density accurately. Many very cheap “floats” can vary significantly, making them completely unsuitable!
In the sea, the pH level is constant, between 8.0 and 8.3, just like the salinity. In the aquarium, a good range is between 7.9 and 8.5. The higher the pH, the less acid is present. A low pH is often caused by a high carbon dioxide level in the water. Better aeration of the water can easily correct the pH. Another cause of a low pH can be a high nitrate level. Therefore, if the pH is consistently low, always perform a nitrate test!
Seeding, as it was once called, refers to introducing the necessary bacterial life into the aquarium. Nowadays, we worry less about this. Because aquariums are now set up with large amounts of live rock, all the necessary bacteria and microorganisms are present in the correct quantities. It is advisable to introduce some fresh live rock at least once a year. A healthy marine aquarium houses hundreds of thousands of species of organisms. Gradually, different species die off, which can be literally thousands of species per year. It is quite possible that one of these organisms is crucial for a specific process. By occasionally introducing some fresh live rock, a lot of trouble can be avoided. Many problems with purple slime are often traced back to a disrupted micro-life in the tank.
It’s natural that after reading the sections on equipment, you wonder what is actually needed.
There are several ways to achieve this, but with the following list, you will definitely not go wrong.
By this, we mean an aquarium with a filter tank underneath, which are often custom-built. This allows for all your preferences to be considered: the color of the cabinet, type of protein skimmer, placement of the overflow, water height, etc. Such an aquarium requires a bit more planning, but you will enjoy it for years. A major advantage is that most of these systems can also be adjusted later to accommodate changing insights. Most hobbyists prefer such a system.
| Not to be purchased yet: a starter stocking (algae eaters, sand-cleaning animals, fast-growing corals that compete with algae). These animals are added to the tank much later! |
Nowadays, there are good ready-made aquariums, complete with protein skimmer, pumps, filter, lighting, etc. These aquariums are generally quite acceptable in quality. However, be aware that the expansion options for these aquariums are minimal. Often, there is no space for a larger protein skimmer or a calcium reactor! If this is not a concern for you and you prefer to buy a ready-to-use aquarium, then this is an acceptable alternative to a custom-built system. Even with ready-made aquariums, you will still need various accessories, such as buckets, salt, a salt meter, test kits, etc. The shopping list is no different from that for custom systems.
And now? You are the proud owner of a well-functioning marine aquarium! Do not buy too many fish at the start; less is more! By following these maintenance instructions, you will encounter few or no major problems. A good retailer, like the one where you got this booklet, can always help resolve any issues. Also, check out the "more information" section. Here, you will find various books and websites with more information about this wonderful hobby. Prevention is better than cure; reading more about this hobby pays off!
It is impossible to cover the population in detail in this topic. We distinguish between two groups of animals in a marine aquarium: invertebrates and fish. The groups are listed arbitrarily and only briefly covered.
Invertebrates:
The animals in the aquarium need to be fed daily. It is also wise to provide as much variety as possible. A diet of frozen Artemia and frozen Mysis is NOT considered varied! Mysis, Artemia, Cyclops, mussel meat, fish meat, and fish eggs, along with high-quality dry food, form the basis. The so-called "algae sheets" are also recommended for herbivores. Live food should also be given as often as possible. Although the nutritional value of live food is low, variety encourages eating. A varied diet helps ensure that the fish eat better and more. It is also a good idea to add vitamins to the food daily!
You can still go on vacation, even if you have a marine aquarium! Of course, the aquarium must be maintained during your absence. Someone needs to visit daily to check that everything is working, top up the water, and possibly feed small (pre-measured by yourself!) portions. Make sure not to buy new animals in the last weeks before your vacation. Doing so can lead to problems. A good store may also provide care for your tank during your absence. Always leave a clear list (and a printout) with exact instructions for the caretaker. It’s smart to have the caretaker perform all tasks while you observe before you leave. This way, you can ensure that the instructions are completely clear. It is also always wise to leave an emergency phone number.
We describe the basic maintenance for systems as they are usually supplied. Typically, the filtration system of such a setup consists of a tank with an overflow, a protein skimmer, and possibly a drip filter. Expansion with various components, such as a calcium reactor, is possible and is also discussed. The evaporated water must be replaced, and water needs to be regularly refreshed. It is best to use water from a reverse osmosis unit for this purpose. This device is commonly referred to as an RO unit among enthusiasts. This unit purifies tap water so that it is suitable for use in aquariums. Tap water contains traces of pesticides, various unwanted fertilizers, plasticizers, and many other undesirable contaminants. Using tap water for your marine aquarium risks algae blooms, unclear problems, and dead animals! RO water is an investment in a healthy and beautiful aquarium!
1. Check if all equipment is still working. Take action if necessary.
2. Check for dead animals. Remove deceased animals immediately!
3. Check for any signs of disease. Never ignore diseases; seek advice and take action immediately!
4. Top up the water.
5. Check the temperature.
6. Feed the fish.
7. Measure and, if necessary, adjust the salinity.
8. Clean or preferably replace the pre-filter (filter wool/filter cloth).
9. Empty and clean the skimmer cup.
10. Add any trace elements if needed.
11. Remove any algae or brush them off with a soft toothbrush.
12. Refresh 20% of the water, and vacuum the substrate to remove debris.
13. Test water quality: pH, KH, calcium level, nitrate, phosphate. Adjust as necessary.
14. During water changes, vacuum all substrate material and rinse or replace it.
15. Clean the reaction chamber of the ozone generator.
16. Clean the pumps.
17. Replace the lamps.
18. Clean the glass.
Explanation of the different points:
Protein skimmers, circulation pumps, and lift pumps are the most critical components. The heater and lighting should also be checked. If there are few or no air bubbles in the protein skimmer but the skimmer pump is still working, the venturi, the component that mixes water and air, is likely clogged. Clear the air intake with a wooden skewer, or rinse the venturi thoroughly with fresh water, preferably with some vinegar.
1. If multiple animals disappear or die simultaneously, or if symptoms of disease are visible, take immediate action!
2. The water should preferably be topped up daily. If it’s only a few liters, it is not necessary to bring the water to temperature. For larger quantities, it is absolutely necessary to bring the water to temperature. Always use RO water for topping up to prevent algae and poisoning problems.
3. The temperature should never drop below 24 degrees Celsius. Problems can be expected below this temperature. Temperatures above 28 degrees are also problematic.
4. Fish should be fed daily, preferably at the same time. Frozen food should be thawed. It is best to discard the water in which the food is thawed, as this water contains many substances (including phosphates) that strongly promote algae growth! Thaw the food in a plastic tea strainer or fine-mesh fish net. Adding vitamins to the food weekly is certainly beneficial!
5. The salinity should be between 1.022 and 1.025 at 25°C. If the salinity is too low, top up with seawater. If it is too high, remove some seawater from the system and replace it with fresh water. Always change the salinity gradually over several days! Also, have the salinity meter calibrated at least once or twice a year. This can be done at a good store.
6. The pre-filter captures debris before it breaks down in the filter. Replace this filter material at least once a week!
7. The skimmer cup should be cleaned at least once a week. It needs to be emptied more frequently if it accumulates more waste. Emptying and cleaning it once a week is the minimum. The liquid in the cup should be dark brown. If the color is much lighter, the water level in the skimmer is too high. Open the outflow valve further, add less water, or reduce the air supply to lower this level. If the liquid is very dark (almost black) and little liquid is being produced, it may be helpful to increase the water supply, reduce the outflow opening, or increase the air supply.
8. Especially in aquariums with invertebrates, it is wise to add trace elements. Trace elements are substances that are slowly depleted and not sufficiently provided through food and water. Various liquids with trace elements are available commercially. Using these liquids can prevent deficiencies.
9. Some algae will always be present in any tank. As soon as algae start to dominate, take action!
10. To remove accumulated waste and address any trace element deficiencies, water should be refreshed monthly. Try to vacuum up as much debris as possible during the refresh. The fresh water should have the same salinity and temperature as the water in the aquarium. Check this before you start refreshing!
11. The water quality should always be optimal: pH between 7.9 and 8.5, calcium level between 380 and 430 mg/l, phosphate at 0, nitrate between 0 and 5 mg/l, KH between 7 and 12.
12. Large amounts of sediment, also known as detritus, often accumulate in the substrate. This sediment can cause various problems over time. To avoid these problems, it is wise to remove this sediment. The substrate can be vacuumed with a thick hose. The old substrate can be rinsed in old seawater or replaced.
13. The aluminum reaction chamber in the ozone generator should be cleaned every two months with the provided brush. Modern ozone generators are easier to maintain: the electrode is often ceramic and can be very easily cleaned.
14. Disassemble all pumps, carefully scrub them from the inside, and soak them in vinegar. Rinse them later with fresh water. Obviously, do not remove all pumps at once; it is important to maintain circulation in the tank during this maintenance.
15. The lamps lose capacity over time. To avoid a sudden change in lighting, all lamps should be replaced once a year.
16. Cleaning the glass is not necessary to keep the animals in the tank healthy. However, it is better to keep the glass clean: dirty glass looks very untidy and can often cause disputes with housemates. Better to be safe than sorry!