- Choosing a suitable aquarium
Environmental stability is the most important aspect of successful saltwater aquarium maintenance. While it’s important to choose an aquarium that you think will look good in your living room, there are other equally important considerations that should influence your judgment. When choosing your aquarium, you will need to think about the ideal environment for the fish. This is especially true if you are planning an aquarium for a specific type of fish that you want to keep in the aquarium, but still, the first priority when choosing the aquarium and the equipment is the stability of the system.
- 1. Acrylic Aquarium or Glass Aquarium
One of the first choices you will make is whether to purchase a glass or acrylic aquarium. Here’s a list of five points to discuss:
– Acrylic is a better insulator than glass, so you’ll need a smaller heater and temperature swings will be slower. This is good for stability.
– Acrylic is clearer than glass. 14% more light passes through it than through glass.
– The acrylic aquarium can have many different shapes. These aquariums often have rounded corners and usually have a more “modern” look.
– A disadvantage of acrylic is that it scratches much more easily (be careful with interior decorations) so special cleaning pads must be used.
– Perhaps the biggest disadvantage of acrylic is the price. Typically, an acrylic aquarium costs 2 to 3 times more than a similarly sized glass aquarium.
- 2. Aquarium size
Always choose the largest aquarium size that fits your living room and budget.
– The size of a saltwater aquarium is critical, as the fish capacity is three to five times smaller than a freshwater aquarium.
– Although we have seen successful marine aquariums that are smaller than 100 litres, which is the smallest size we can recommend, 220 to 400 litre tanks are much more desirable.
– The larger the aquarium, the greater the chance of success.
- 3. Aquarium surface
– Always choose an aquarium with as large a surface as possible.
– The amount of dissolved oxygen is mainly determined by the size of the surface of the aquarium.
– It seems that despite aeration with an air stone or a powerful pump, the movement of water from the bottom of the aquarium to the surface, where oxygen is exchanged with carbon dioxide, contributes more to the saturation of oxygen in the water.
- 4. Saltwater Aquarium Lighting
The lighting for a saltwater aquarium cannot be like that used for a freshwater aquarium. Marine aquarium light has a specific spectrum. Aquariums are usually purchased as a “combination”, meaning a glass tank and a light fixture. Bulbs are purchased separately. The majority of aquarium lighting fixtures in the past were designed for use with fluorescent lamps, while the new technology available shifts the focus to new LED lights with adjustable spectrums and program controlled light intensities.
- 5. Aquarium furniture
All aquariums also need a good, solid stand (cabinet). Most manufactured aquariums are standardized in size, and there are a variety of stands built for every aquarium size. Many cabinets also have a cover for the top of the aquarium. Although not absolutely necessary, a cover adds a finished look to your “exhibit” and most covers are designed to mount aquarium lighting.
2. Building a saltwater aquarium
Five steps to building your first saltwater aquarium:
We offer you a quick guide to setting up a marine aquarium in five easy steps. A list of necessary marine supplies (techniques) and step-by-step how to place them in the aquarium. Only after that – how to prepare the water, how to test the water and finally about adding your fish!
2.1. Equipment for the marine aquarium:
Aquarium:
Buy as much as possible, a bigger aquarium with strong aquarium stand and aquarium lighting. Most aquariums are sold in combination with a light fixture.
Filter:
For a “fish only” “FO” aquarium, it is best to have a sump- built into the aquarium itself (in its rear part) or an external sump – located under the aquarium. A sump is a separate aquarium with different compartments that house the filter media, the skimmer, the heater, etc. Water enters the sump through an overflow column and returns to the main aquarium with the help of a submersible pump.
Another option is a bottom filter. It provides stability and is easy to maintain. Electric filters (canisters) also work well, but the stability of the aquarium can be compromised when you do maintenance!
NOTE: care must be taken with canisters when changing filter media. They contain many beneficial bacteria for biological filtration. A filter with two cartridges is the best in this case, since you can change only one and not disturb the bacterial balance. This will help to maintain good bacterial cultures.
Skimmer: Get a skimmer according to the size of your aquarium. Neither bigger nor smaller! A 24-volt pump is preferable to a 230-volt pump. The low voltage pump runs much more smoothly and does not change its flow rate as the voltage in your installation changes, which affects the quality of the foam.
Substrate: Provide at least 2 – 3 cm of substrate. Fine coral sand, aragonite or quicksand are the best substrates, but also inert quartz sand can be used. Do not use substrate intended for freshwater aquariums.
Heater/Thermometer: Get a heater with a thermostat suitable for the size of your aquarium and a thermometer. We prefer a thermometer that attaches to the aquarium for easier viewing. If you have a large tank, you may be more comfortable with one on each end.
Aquarium salt and hydrometer: Get a hydrometer to measure the salinity (specific gravity) of the water and good quality salt for marine aquariums. Take enough salt to salt 1 1/2 times the volume of the aquarium. DO NOT USE ANY OTHER TYPE OF SALT EXCEPT SALT INTENDED FOR USE IN MARINE AQUARIUMS.
Water: DO NOT use distilled water. Purified water is the best choice, but not required. For purified water, use R/O (reverse osmosis) or deionized water. If purified water is not used make sure you buy some kind of softener that removes chlorine if you don’t know if there might be chlorine added to the water. Better safe than sorry.
Aquarium Tests: Get saltwater tests for ammonia and nitrites (this is the bare minimum to start with, you’ll get more later if you need them). Carbonate hardness, Nitrates, Phosphates, Calcium and Magnesium are the main parameters you need to test and adjust on weekly basis to maintain a healthy reef tank.
Aquarium Decor: Now is a good time to buy any decorations that match your fantasy. Saltwater fish feel more secure and comfortable with more shelters. Coral skeletons and live rock are good choices which are also beneficial, but other artificial ornaments are also suitable.
2.2. Construction of the marine aquarium
– Place the aquarium on a reliable base (floor) in a suitable place.
– Rinse the primer (substrate) thoroughly and then place it on the bottom of the aquarium.
– Fill with water. For the first time, the salt can be added directly into the aquarium while filling, but afterwards it has to be mixed separately before adding it to the aquarium. Make sure the specific gravity is between 1.020 and 1.025.
Note: Always mix the salt and water separately before placing it in the active aquarium!
– Place the heater, ornaments, thermometer and all lights in or on the aquarium.
2.3. Starting the aquarium
– The aquarium must be “running” for at least 24 hours. During this time, the water oxidizes and the salt is stirred for at least one full day (24 hours).
– Make sure the temperature stabilizes at an acceptable level between 23-26 degrees.
2.4. “Cycling” the aquarium
– Establishing and maintaining the nitrifying cycle is one of the most important parts of a successful marine aquarium. In most cases, it is necessary to add products with nitrifying bacteria for faster maturation of the aquarium. Adding live rocks significantly decreases the time of the cycling process.
-The aquarium needs live fish to complete the cycling process. The nitrifying bacteria as well as the live rock helps catch the ammonia peak during the cycling process and keep the fish alive, but the aquarium needs CO2 and other organic matter and debris produced by fish in order to finish the cycle and stabilize.
2.5. Monitoring Ammonia and Nitrite Levels
– Test ammonia and nitrite levels until they reach zero (or very close to zero).
– During this aquarium cycle, ammonia will first peak and then begin to decline to give way to nitrites.
– Once levels drop to zero, add fish slowly and monitor ammonia and nitrite levels, to make sure the aquarium is stable.
3. Filtration in the saltwater aquarium
There are three main types of filtrations used in saltwater aquariums. Several other methods that are more commonly used in reef systems may also be useful for fish-only systems and will also be mentioned here.
3.1. Biological filtration
This is the most important type of filtration for stability and reduction of toxic waste. In any biological environment there is production of ammonia from normal respiration (fish release ammonia from their gills) and from the decomposition of waste. Ammonia is toxic to fish, but through biological processes, it is converted into a non-toxic chemical, nitrate.
The nitrification process:
Nitrification is the process of converting ammonia into nitrates, and it takes place in the presence of oxygen (aerobic conditions).
- First, the ammonia is reduced to nitrites by a bacteria called Nitrosomonas. Unfortunately, nitrites are also poisonous to fish.
- The nitrites are then broken down into nitrates by bacteria called Nitrobacter.
- The end product, nitrate is relatively harmless to fish and is a staple food for plants, algae and corals. Frequent water changes (say 10-15% each week) will keep nitrate levels within tolerable limits.
The denitrification process:
Denitrification is a process in which nitrates are converted into nitrogen gas in the absence of oxygen (anaerobic conditions). Denitrification is of great importance to marine aquaristics, especially if there is no other way to control nitrates.
A place for biological filtration
Since this filtration is done by bacteria, it is necessary to provide a place for them to settle and nutrients to help their work.
– Live rock and live sand
Live rock and live sand are used in reef and marine systems as a biological filter. An added bonus of live stones are de-nitrifying bacteria deep within the stones, helping to remove nitrates. At least 5 cm of live sand should be used if relying on it alone for biological filtration, live stones should be 0.5 to 1.0 kg. per 4 liters of water.
– Carbon sources – limiting nutrient for bacteria
They are solid (bio pellets) and liquid (dosed daily). Bio pellets are placed in special reactors to be effective.
– Trickle-filters (boiling filter)
Nitrification is more efficient in the presence of oxygen. The water in this filter contains about 20% oxygen compared to aquarium water which is only about 7% oxygen. Trickle filters or Wet/dry filters, developed in the 1980s, dramatically increased the efficiency of biological filtration.
In Trickle filters, the bacterial culture medium (filter balls with large surface areas) is placed in the air, usually outside the aquarium. In this way, the water flows through the filter media. Many types, sizes and shapes of trickle filters have been used since they were first introduced. Although many Trickle filters are external devices used in the sump or hang on the back of the aquarium, several manufacturers build Trickle filters into the back of the aquarium itself.
The problem with the original Trickle filters is that they usually produce too high levels of nitrates, and are therefore not often used in reef aquariums or other situations where nitrates are undesirable. Recently, modified bio-polymer pellets (not round) have been used for filter media – having the ability to remove nitrates as well.
– Bottom Filter
Bottom filters have been the most common type of biological filtration in the past and work by pulling water up from below, through the gravel bed at the bottom of the aquarium and pumped up through riser pipes. There are also reverse bottom filters where water is pulled from the top of the aquarium and fed down through the gravel. Backflow filters are slightly more efficient because they take water from the top of the aquarium, which contains more oxygen.
3.2. Mechanical filtration
Mechanical filtration is the removal of dust particles from the aquarium. Debris, food scraps and other particles are “mechanically” collected in the filter media. Mechanical filtration is good for keeping the water clear and free of detritus.
Types of mechanical filtration:
– Sump and filter wats
A sump is a separate tank under the aquarium or in another room or partitioned part of the very back of the aquarium. Its main purpose is to provide a place for different types of mechanical filtering devices or simply filter media (wadding, phosphate adsorbers, activated carbon, skimmer). The water passing through it has a low speed.
– External filter (canister)
A compromise option for marine aquarium filtration. The densely packed media inside the canister act as a mechanical filter. The filters must be cleaned periodically, as they collect a lot of detritus.
-Bottom filters
Bottom filters, although primarily used for biological filtration, also act as mechanical filters by trapping debris in the gravel. Debris is cleaned by siphoning the sand when the water is change.
3.3. Chemical filtration
Chemical filters are used to remove substances that dissolve in water and therefore cannot be removed by mechanical filters. They are useful to get rid of the yellow colour that often develops in the aquarium over time. The filter media with the chemical adsorbers are placed in special reactors or, as a last resort, in a bag and then placed in the sump or canister.
Types of chemical filters:
– Activated carbon
The most common chemical filter is activated carbon, which is mostly used in a reactor. Activated carbon traps many substances in its pores.
According to Martin A. Moe Jr., in his book The Marine Aquarium Handbook, some of the substances removed by activated carbon are copper, ozone, chlorine, antibiotics, some dissolved proteins and carbohydrates, iodine, mercury, cobalt, iron, methylene blue, malachite green, sulphonamides, organic dyes, as well as many other elements and compounds.
Note: Many aquarium medications, including antibiotics, are removed by activated charcoal and therefore should not be used in treating aquarium disease.
– Zeolites
Other types of chemical filter materials, called zeolites, have been developed to remove specific compounds such as nitrates and phosphates. Normally, a marine aquarium with only fish does not need these types of filtrations, but they are often used in mini-reefs.
– Other chemical agents:
Phosphate removers – are chemical adsorbers of phosphates, and it is best to place them in special reactors and periodically test the level of phosphates, because they have a certain adsorption limit and stop working after reaching it.
Note: Nitrate and phosphate control is generally not necessary in saltwater fish-only aquariums unless levels become very high or there are ongoing problems with unwanted algal blooms.
3.4. Other types of filtrations:
– Protein skimmer – the heart of the marine aquarium!
Protein skimmers work by passing a large stream of tiny bubbles through a column of aquarium water. Many different substances (proteins) stick to the surface of the bubbles. Thus, they are removed from the water in the pores of the foam, which rise to the top.
Advantages:
Protein skimmers are useful because they remove waste matter before it enters the nitrification cycle.
This reduces the production of nitrates and increases the oxygenation of the aquarium water.
Disadvantages:
One of the disadvantages of skimmers is that they remove trace elements and iodine. If these elements are necessary for the inhabitants of the aquarium, they should be added periodically.
– UV – Ultraviolet sterilization
Ultraviolet sterilization works by passing water through ultraviolet light. If the water is exposed long enough and in a high enough concentration of light, bacteria, algae and parasites can be killed by the light.
- UV is widely used for ponds to help fight algae (green water).
- When treating diseases in the aquarium, a strong exposure to UV light is required.
- The strength of the light depends on the size of the aquarium. For the needs of marine aquaristics, powerful lamps are needed – over 20 watts.
– Ozone
Ozone passes through the aquarium water to oxidize all forms of organic pollutants and kill many of the same organisms that UV ultraviolet radiation does. Often used in protein skimmers which must be made of “ozone safe” materials, and the water must necessarily pass through activated carbon before returning to the aquarium. Note: any residual ozone in the water is extremely toxic to fish.
4. Selection of saltwater fish
The most enjoyable part of creating the aquarium is choosing the fish. There are many great saltwater fish and even some invertebrates that do very well in a fish only tank. When choosing the inhabitants for your saltwater aquarium, you need to consider the size of the tank, the compatibility of the housemates and their food requirements.
– Saltwater aquarium capacity
The first thing you need to know is how many fish you can keep in a certain size aquarium. The number of fish you can safely keep in a saltwater aquarium is 1/3 to 1/5 less than in a freshwater aquarium. Be careful not to overpopulate the aquarium as this can have devastating results. It is better to have fewer fish that are colorful and healthy than to max out your tank and run the risk of losing one of your fish. Not only will the fish be happier, but maintenance is also easier.
Formula for determining the number of fish:
- Common Formula
The most common formula for the number of saltwater fish you can safely keep is based on the volume of the aquarium. The rule of thumb for the number of fish in a saltwater aquarium is that there should be 3 liters of water for every 1 cm of fish.
This simple method does not take into account the surface area of the water (for oxygen saturation), the filtration system (for removing waste products) and the overall size of the fish. For example, one fish that is 6 cm in length needs much more oxygen than six fish that are 1 cm in length. In general, the number of fish should be reduced if they are larger, and you can increase the number of fish if they are smaller. Another method is to:
- aquarium area formula
Calculate the surface area of the aquarium and divide by 120 to get the number of fish in cm the aquarium can handle.
This method takes into account the shape of the aquarium but does not take into account filtration or the size of the fish. The second formula favours aquariums that are shorter and wider over aquariums that are taller and thinner.
- Other formulas
There are other formulas, but they are more complicated. In general, it is not worth calculating if you are not approaching the maximum number of fish calculated from the above formulas.
4.1. Saltwater aquarium – Type of fish community
You should have some idea of what kind of fish you want to keep before you buy them. Decide if you want a general aquarium or a species aquarium. Research each marine fish before adding it to your aquarium. Learn more about the needs and temperament of each species you want to keep. This will help avoid later compatibility problems and also avoid food competition.
Some fish are predatory or aggressive so they should only be seen with conspecifics or other predatory species. For example, a pure carnivore aquarium may contain lionfish, eels, triggers and groupers. Smaller fish, like Damsels and Cardinals can quickly become their lunch!
Note: Aggressive species are many triggerfish, damsels (especially as they age) and some angelfish and groupers. Tangs can become territorial and aggressive towards other tangs that were added later. To avoid this, you can change the decoration in the aquarium before adding a new Tang to a populated aquarium.
-Some fish are slow feeders or very shy and need to be kept alone in a special aquarium. Examples of this are the razor fish (shrimp fish) and seahorses.
-Some fish only feed on live food. Make sure you can provide the necessary food for the fish.
5. Saltwater aquarium maintenance
Once the aquarium cycles have passed and you already have fish, regular care is needed to keep the aquarium stable, which is a guarantee of the health of the fish or other inhabitants. Here are some general feeding and maintenance tips:
5.1. Feeding
Make sure you know all special feeding requirements of the fish before you buy them and be sure you can provide them with the food they need. Some fish may require special diets such as butterflyfish, some angelfish, parrotfish and anthias. It is easy to find fish that require coral polyps or sponges for their diet. Corals are impractical and very expensive to buy as food, but some food manufacturers include mushrooms in their frozen foods.
-Some fish are used to eating all the time and they should be fed as often as practical. Always small amounts at least once a day.
-Other fish such as eels can go several days without food.
-Encourage your fish to eat as many different types of food as possible. This will ensure that they get everything they need.
-The more fish are fed, the faster they will grow to their maximum size.
5.2. Water changes
Marine aquarium systems require partial water changes on a regular basis. Some of the reasons for water changes are to remove nitrates, replenish micronutrients, and to clean the gravel of accumulated detritus. Detritus is a greyish pile of waste products that accumulates in the aquarium.
– It is recommended to change the water about 25% per month.
– When deciding how much and how often you want to do water changes, keep in mind that for a stable aquarium, smaller water changes done more often are better than large water changes done less often.
Note: Water changes are more frequent than recommended for freshwater aquariums.
– It is a good idea, although not absolutely necessary, to use water that is filtered either by reverse osmosis or by deionization. Distilled water can be used along with good sea salt, but it costs quite a bit more than reverse osmosis or deionized water.
Note: The use of distilled water is generally not recommended.
– Add salt only when changing water that has been drained outside.
– Add fresh water without salt when you replace (top up) water that has evaporated (which happens every day). THE SALT DOES NOT EVAPORATE WITH THE WATER!