Setting up & obtaining the right salinity
The initial setup of a marine tank is somewhat more complicated than that of a freshwater tank. Most crucially, synthetic sea salt must be added to produce water with the proper salinity/specific gravity.
Since with a freshwater system, your saltwater aquarium should not be placed in direct sunlight, as this promotes algae development and may lead to overheating. You should also ensure that the surface is level and capable of supporting the weight of your aquarium, and you should strive to position the tank so that it is not vulnerable to knocks and bumps. Although a strong impact is required to shatter the tank, other blows might stress the fish.
Putting up a salt water aquarium is much the same as setting up any other aquarium, save from the addition of salt. Before adding the substrate, it should be cleaned, and the tank should be in place before filling. If you are fitting a backdrop, it is best to do so before putting the tank in place.
Once the tank is in place and the substrate is in place, you may begin adding water. You may add the salt and water in two ways. The first step is to add the salt water bucket by bucket to the tank. This is good for a small aquarium, but in bigger tanks it may be time consuming. The second way is to fill the tank largely with freshwater before adding the salt.
Method one: To make a bucket of salt with the proper salinity, you must first know two things. First, consider the size of your bucket. Remember that you will seldom fill the bucket completely, therefore write a line with a water proof marker to indicate a certain capacity. Second, you must know how many grains of salt are required per litre. This is typically about 33 grammes per litre, although varies somewhat across brands. If the packet does not clearly include this information, you can typically figure it out. The packaging should at the very least include the weight of the salt and the total volume of salt water it will produce. To calculate the amount of salt required per litre, divide the weight (in grammes) by the volume (in litres). When given the weight of salt in kilogrammes, multiply by 1000 to obtain the weight in grammes. For example, if a 10kg box contains 300 litres, divide 10000 g by 300 litres to get 33.33g/litre. Rounding to the next gramme is close enough in this situation, so use 33g/litre.
Because it is difficult to estimate the exact amount of a bucket, it is preferable to put in slightly less salt than you believe you will use (This is especially true when filling the tank because any error will be multiplied by the number of buckets you are adding). You can always add more salt later, but if you add too much, you will lose any salt that has already dissolved.
Add the salt in buckets until the tank is about three-quarters filled (or at least until the filtration and heating can be started). Turn on the filtration and heating (if applicable) and keep them running for at least 12 hours. This ensures that the salt is completely dissolved and that the temperature is appropriate for testing the specific gravity. After you’ve determined the specific gravity, you may finish filling the tank and, if necessary, adjust the salinity. If your specific gravity value is too high, for example, use less salt per bucket (or add some purely fresh water). If the specific gravity is too low, add a little extra salt per bucket (again, don’t overdo it; you can always add more salt later if necessary).
Allow the tank to circulate for a few hours after it is filled before re-checking the specific gravity. If this value is excessively high, part of the salt water must be removed and replaced with freshwater. If the specific gravity is too low, add a little quantity of salt (one to a few hundred grammes) at a time. Before adding the salt, mix it with a little tank water to facilitate dissolution. Allow the water to circulate for approximately 30 minutes after correcting the salinity before re-checking the specific gravity and making any necessary changes.
Method two: It is typically easier to fill the tank largely with freshwater (e.g., via a hose) and then add the necessary quantity of salt. To calculate how much salt is needed, you will need to know the amount of your tank as well as the grammes of salt necessary per litre. This is typically about 33 grammes per litre, although varies somewhat across brands. If the packet does not clearly include this information, you can typically figure it out. The packaging should at the very least include the weight of the salt and the total volume of salt water it will produce. To calculate the amount of salt required per litre, divide the weight (in grammes) by the volume (in litres). When given the weight of salt in kilogrammes, multiply by 1000 to obtain the weight in grammes. For example, if a 10kg box contains 300 litres, divide 10000 g by 300 litres to get 33.33g/litre. Rounding to the next gramme is close enough in this situation, so use 33g/litre. Volume in litres may be readily computed for rectangular tanks by measuring the length, width, and depth in centimetres, multiplying these dimensions together, then dividing by 1000. See here for further information and instructions on determining volume in tanks of different forms.
The required quantity of salt is then determined by multiplying the volume in litres by the grammes per litre. For a 200-litre tank, multiply 200 litres by 33 g/litre to get 6600 grammes, or 6.6 kg. However, calculating the precise amount of water in an aquarium is difficult since some water will be displaced by the gravel and decorations. As a result, we usually advise applying less salt than this determined quantity. You can always add more salt later, but if you add too much, you will lose any salt that has already dissolved.
After you’ve added the salt, switch on the filtration and heating and let the tank to circulate for at least 12 hours. This ensures that the salt is completely dissolved and that the temperature is appropriate for testing the specific gravity. If the specific gravity is too high, part of the salt water must be removed and replaced with freshwater. If the specific gravity is too low, add a little quantity of salt (one to a few hundred grammes) at a time. Before adding the salt, mix it with a little tank water to facilitate dissolution. Allow the water to circulate for approximately 30 minutes after correcting the salinity before re-checking the specific gravity and making any necessary changes.
Cycling your marine tank
Cycling is a process that happens almost silently in every aquarium, whether fresh and saltwater. When stocking a new aquarium, understanding this technique will help you reduce fish losses. Because saltwater fish are more sensitive, understanding this process is much more critical.
Hazardous waste products are excreted by all fish and are broken down into less toxic molecules by naturally existing beneficial bacteria. These healthy bacteria gradually cover all surfaces in the aquarium and settle in huge numbers in the filter, but in a fresh new aquarium, relatively few of these good bacteria are present, allowing hazardous wastes to amass fast. As a result, it is critical not to introduce too many fish at once; instead, gradually increase the fish population until these helpful bacteria develop and expand into sufficient numbers to eliminate the poisonous wastes. Leaving the tank empty, on the other hand, is fruitless since these bacteria cannot develop and establish without the wastes from the fish, and the tank stays sterile. Cycling refers to the process of accumulating these beneficial microorganisms. Good bacteria may be introduced to aid this process by utilising a product such as Hagen cycle.
There are two kinds of microorganisms at work. The first type, known as Nitrosomas, converts ammonia to nitrite. Ammonia is created in the aquarium by the fish, as well as uneaten food and other decomposing organic debris. Ammonia is very poisonous to fish, and its toxicity increases as the pH rises. As a result, ammonia is far more harmful in salt water (which has a pH of roughly 8) than in freshwater (where pH is usually around 7). Nitrospira bacteria are the second kind of bacteria that convert nitrite to nitrate. (Note: Nitrobacter were formerly assumed to be responsible for this, however Nitrospira seem to be the primary species in aquaria that breakdown nitrite.) Nitrite is not as poisonous as ammonia, but it is still damaging to fish, and certain species are more vulnerable.
Ammonia will accumulate in the aquarium throughout the cycle process until the Nitrosomas bacteria population becomes big enough to regulate it. As they convert ammonia to nitrite, ammonia levels fall while nitrite levels increase. Nitrospira may begin to proliferate once nitrite is present. Naturally, this takes time, so nitrite levels might rise until the second wave of healthy bacteria takes hold. Once both sets of beneficial bacteria are in place, ammonia and nitrite should be undetectable, and nitrate should begin to accumulate. Nitrate is not normally broken down in the aquarium and may only be eliminated by frequent partial water changes.
Cycling may be monitored by testing for ammonia and nitrite. This is highly recommended since it allows you to save fish if excessive levels of ammonia and/or nitrite are detected. Second, you will know when it is safe to add additional fish or when more delicate species may be introduced.
Even if both types of bacteria are present, it is critical not to introduce too many fish (or other animals) at once. More fish means more ammonia, thus more beneficial bacteria are required. The bacteria will multiply to deal with the increased wastes, but if too many fish are introduced at once, the system may become overwhelmed, and ammonia or nitrite levels may rise to hazardous levels. Overfeeding may also result in harmful waste buildup, therefore feeding should be done with caution, especially in a new tank.
Extra caution is required in salt water since the fish are more sensitive and ammonia is significantly more poisonous at higher pH. You should also consider the sort of fish you wish to maintain, since this will influence how you approach the cycle process. As previously stated, the aquarium will not cycle on its own, i.e. when empty, thus you must add some form of fish or other animals to begin the process. There are three typical approaches:
- Mollies: Mollies are a kind of fish that is often offered for freshwater tropical tanks, but they can also thrive in salt water. They are an excellent fish for cycling the tank for a variety of reasons. For starters, they are tough and can withstand high levels of ammonia and nitrite. Second, they are highly dirty, which is ideal from the standpoint of cycling since it promotes the development of a huge number of helpful bacteria. This is our suggested cycling technique, particularly for fish-only tanks and newbies, since it is inexpensive and practically failsafe. Of course, mollies may not be compatible with your ultimate choice of fish, but they can generally be traded in when you’re ready to buy other marine species.
- Hardy marine fish: Hardy marine fish may be employed if your aquarium is properly filtered and set up. If you utilise this approach, it is strongly advised that you take a bacterial supplement to seed the filter with healthy bacteria. Clownfish, damsels, and tough wrasses such as lunar or lutescens wrasses are the best options. Eels and Lionfish are also fairly resilient, so if you want to retain them, they may also be used for tank cycling. However, none of these are as tolerant as mollies, so be prepared to monitor the water regularly and make a water change if necessary to reduce harmful ammonia and/or nitrite levels.
- Living rock: formerly a popular option, it is no longer so, particularly in fish-only systems. Although adding live rock is a simple approach to cycle the tank, it is fairly costly when compared to other ways. Furthermore, the little creatures on live rock may only encourage the development of a limited number of helpful bacteria, so when introducing marine fish, care must be taken to ensure that enough bacteria are present to deal with their wastes. If you want to have live rock in your tank, whether it’s fish-only or reef-only, you need add rock first. There is always the possibility of die-back on rock put to a new aquarium, which may result in large ammonia surges that are toxic to fish. After adding the rock and monitoring ammonia/nitrite levels (see below), you may introduce moillies or a hardy marine fish and monitor levels until you are certain the cycle is complete and the tank is suitable for more sensitive species. A reef aquarium is the only place where rock is advised as the ideal place to start cycling. In a reef, you almost always want a lot of rock, and the tank will have less fish. (For further information, check the next section.)
Other approaches, like as directly adding ammonia to the tank, are utilised with varied degrees of effectiveness. It is advised that you test your water on a frequent basis while the tank cycles, regardless of the technique you choose. Check the nitrite levels in particular: after the nitrite concentration has peaked and begins to fall, both kinds of helpful bacteria are present and established in the filter. This does not imply that the tank is totally mature; the quantities of these bacteria will continue to rise over time, but it does imply that the fish (or other livestock) load may be progressively raised and more sensitive species introduced.
After you’ve selected and acquired your first fish, they must be acclimated to their new home. When you bring your fish home, float their sack for 10 to 15 minutes, unopened. This enables the fish to rest and take in their new surroundings until the temperature equalises. If you want to ensure that your fish settle in properly, put some of your tank water to the bag after this time and leave the fish for another 10 to 15 minutes before releasing them.
Some fish, such as mollies, scats, and monos, can survive in both fresh and salt water. If you buy them and they have been maintained in freshwater, you will need to convert them to salt water. It’s better to do this in a large bucket or other similar container. Place the fish in the water they came in into the bucket after floating them to acclimate to temperature. Add a cup of salt water from your tank every ten to fifteen minutes for around two hours, or until the fish are in practically pure salt water. Then net or dump them into the tank carefully.
Testing the water
Once you’ve introduced fish and started feeding them, they’ll start creating ammonia, so that’s the first thing to look for. During this important time, we suggest checking ammonia at least every few days, or whenever you suspect a problem (check the fish for signs of stress such as faded colours, gasping, unusual behaviours). Because the toxicity of ammonia is pH dependent, you should test the pH at the same time to determine the precise quantity of dangerous ammonia. At higher pH levels, ammonia becomes more hazardous. If the dangerous ammonia level is more than 0.05ppm, or the fish seem stressed (gasping, fading colours), conduct a water change but do not clean the filter. In severe circumstances, adding a bacterial supplement and, in extreme cases, an ammonia remover will assist to reduce the quantity of poisonous ammonia. A bacterial supplement will not drop the levels as rapidly as an ammonia remover, but keep in mind that the goal is to develop these healthy bacteria in the filter, and they need some ammonia to thrive on.
Nitrite is created after the ammonia content has peaked and is decreasing. Begin testing for nitrite two weeks after introducing the first fish, or when you detect a significant drop in ammonia content. Nitrite is less poisonous than ammonia, yet it may be harmful at quantities greater than 0.3ppm or in sensitive species. If the concentration is more than 0.3ppm or the fish look disturbed (e.g., fast breathing, rushing about, gasping, abnormally bright colours), make a water change without disturbing the filter. A bacterial supplement will be beneficial.
Both types of beneficial bacteria establish themselves in the filter after nitrite has peaked and begins to fall. This does not imply that the tank is completely mature; the numbers of these bacteria will continue to accumulate over time. However, it should now be safe to introduce more delicate fish. Remember that the load should be progressively raised to enable the number of beneficial bacteria to grow proportionally. Checking ammonia and nitrite levels after introducing new fish is a good idea, as is checking them on a regular basis (every week to few weeks) or if you suspect an issue with the water quality. The primary items to look for on a regular basis, though, are the right pH and nitrate level.
Because nitrate is not normally broken down, it will build up in the aquarium. Other wastes accumulate and tend to lower the pH, making the water more acidic. Although not as hazardous to fish as ammonia or nitrite, nitrate promotes ugly algae development and may be stressful in high concentrations over lengthy periods of time. Because most marine invertebrates are very sensitive to nitrate, nitrate levels should be carefully monitored wherever they are maintained. A pH that is too low might also be detrimental to fish. Salt water’s pH is inherently constant, and the fish will not accept a drop in pH. Weekly nitrate and pH testing will verify that maintenance is appropriate and water quality is acceptable.
It is also critical to verify the specific gravity of saltwater on a regular basis. Evaporation may be substantial in open-topped tanks or if overflow or trickle filtering is utilised, causing specific gravity to increase. In these cases, test the specific gravity twice a week, and if it rises, fill up with fresh water treated with an appropriate water conditioner. When adding freshwater, take care not to pour it straight on any marine species. In other systems, checking specific gravity once every two weeks is typically adequate, although you may want to check it weekly at first to ensure that evaporation is not an issue.
Regular partial water changes are required to eliminate nitrate and acidic dissolved pollutants that the filter system does not break down. The water removed during water changes must be replaced with salt water, which should be mixed ahead of time. It is often advised to prepare the salt water ahead of time, however this is not always necessary. It is best to prepare the salt water the day before, but in the event of an emergency water change (for example, to eliminate ammonia or nitrite), the salt water may be mixed up just before the water change.
If you have a big enough container, you may wish to make a large batch of salt water to have on hand for water changes. Alternatively, in a bucket, combine enough salt for a single water change (or buckets). To manufacture salinity-correct salt, you’ll need to know the capacity of your bucket (or other container) and the grammes of salt required per litre, both of which you should have calculated or knew when you set up the tank (see here). Weigh out the necessary quantity of salt and dissolve it in the water by aggressively swirling or by using a water pump or airstone. A high-quality water conditioner should be included as well. If you always use the same size bucket, you might want to package up pre-weighed bags of salt enough for one bucket so you can perform a quick water change if necessary.
Siphoning water from an aquarium is usually the simplest way to remove it. A length of plastic hose, as well as gravel cleaning syphons, may be employed. Gravel cleaners are suggested since they remove debris from the gravel bed while also removing water for a water change. Before doing a water change, check the specific gravity; if it is too high, add more freshwater while filling up the tank; if it is too low, apply more salt.
Saltwater algae development, like freshwater algae growth, is dependent on the availability of dissolved wastes and light. Excessive algal development is encouraged by too much light, too lengthy a light cycle, or allowing nitrate and other pollutants to accumulate. Even if the water quality is acceptable and the illumination is enough, some algae may form. Diatoms, in particular, which produce a thin browning coating on the glass and other surfaces, are common in freshly set up tanks. This isn’t a huge source of worry. Unless left too long, this sort of algae is readily removed off the glass. This algae will generally give place to green algae as the tank grows. A little amount of green algae is useful because it consumes part of the nitrate and offers an alternate food source for vegetarian fishes like tangs. Green algae will not grow out of control if circumstances are favourable, but if growth becomes excessive, check nitrate levels, do a water change, and remove excess algae. In contrast to freshwater, there are no chemical algicides that are both safe and extremely effective. There are also less algae-eating fish. Fortunately, salt water algae grow slowly and can be managed with proper aquarium care. There are still certain fish that can aid, such as tangs, dwarf angels, and blennies. Furthermore, numerous snails, starfish, and urchins consume algae and assist to keep it under control.
Slime algaes, which may be red or blue-green in colour, are the most common problem algae in marine aquariums. Instead of genuine algae, they are photosynthetic bacteria. These are more common in areas with high phosphate levels. Phosphate tends to accumulate in aquaria where water changes are insufficient, but it is occasionally found in tap water. While phosphate is not toxic to fish or most invertebrates, it does promote the growth of undesirable algae. If the problem is caused by tap water, you may use phosphate binding chemicals or phosphate removal chemical media to help. If it is not your tap water, making further water changes is the best solution. In either situation, syphoning out the algae is advised.
As previously stated, marine fish are more temperature sensitive than freshwater fish, and invertebrates cannot tolerate lengthy periods of high temperature (e.g., over 28°C). Although aquarium heaters may be turned off when not required (for example, in hot weather), they cannot chill the water. Chilling systems are available, but they are beyond of reach for many enthusiasts. They may be necessary to preserve certain temperate marine species, but the following methods should keep the temperature from creating too many difficulties for tropical marines.
First and foremost, ensure that filter is cleaned on a regular basis and that it is operating properly in the summer for optimal water oxygenation. Run an airstone for additional aeration to be sure. Warmer water stores less oxygen, and it is generally low oxygen content rather than temperature that creates issues.
On really hot days, switch off the lights to keep the temperature from rising too high. Even fluorescent tubes produce some heat, mercury vapour and metal halide systems produce a lot. Direct a breeze across the water surface (leave hoods open and lids off or ajar) to help cooling. Perform a water change using cooler water, or, in very severe cases, float a small bag of ice or bottle of frozen water in the tank. Take care if doing this – you don’t want to drop the temperature too much or too quickly, as this causes even more stress on the fish in particular.
Correct diet & feeding
Marine fish have quite specific dietary requirements, and many can be fussy feeders. Specially formulated flakes and pellets are available, but is is strongly recommended to include frozen foods as a part of the staple diet. Most marine fish do best on two to three small feeds per day, rather than one larger feeding. For small marine fish such as clowns, damsels and butterflies some of the best frozen foods are brineshrimp, daphnia mysis shrimp, plankton and bloodworms. For larger and predatory species, feed less often, no more than once per day, and try krill or mixed marine dinners that use fish and shellfish meat. Fresh or thawed whitebait or other small saltwater fish are also suitable. Using goldfish as feeders is not recommended, these are poor nutritionally and can carry disease. For vegetarian fishes, include dried seaweed or vegetable rich frozen foods. Spirulina and shrimp based dried foods can also be included in marine fish diets.
Some invertebrates also require feeding. Many will catch small food particles from the water, but to be sure they are getting food, place some frozen food nearby, or, into their tentacles in the case of anemones. To feed corals and filter feeders (eg fan worms) liquid emulsions are available. Invertebrates (and many fish) also benefit from the addition of other vitamins and minerals. Corals in particular may require supplementary calcium and a range of other minerals.
Maintaining fish health
As with freshwater fish, prevention of disease is much better than cure. In fact, this is even more true of marine fish. There are actually fewer diseases that affect marine fish than freshwater fish, however, many of these can be harder to treat once they have taken hold.
Prevention: The most important factor is maintaining good water quality. Secondly, make sure fish are compatible. Adding a gentle broad spectrum medication when new fish are introduced is highly recommended. UV sterilisers are one of the best disease preventatives available for salt water – they use UV radiation to actually destroy disease causing agents, greatly reducing the chance of infection.
Treatment: Not all fish medications are safe for use in salt water, and only very few can be added where invertebrates are present. If you do need to treat your fish, make sure you get a medication which is safe. Some medications, such as strong antibiotics, should be applied as a short term bath in a separate container (eg a bucket) so as not to harm the filtration bacteria. A quarantine tank can be very useful both for preventing the introduction of problems into the main tank or for treating sick fish.