Aquascaper
Fish Aficionado
There are many, many products available to us for ‘dosing’ our tanks with essential elements and compounds to help our tanks maintain healthy levels. However, there are some that are essential and some that are verging on pointless. Many people have different views on this subject but all are united in the belief that you should never add any chemical element or compound to your tank that you cannot test the level of.
Below is a list of the most common elements and compounds found in saltwater tanks along with basic details on their use or effect: (Sources: Salifert, www.liveaquaria.com)
Ammonia (NH3)
Ammonia should be rapidly converted by aerobic nitrification into Nitrite and then Nitrate and finally into Nitrogen gas. It is a highly toxic element produced by fish waste, decomposing organic matter and foods. It is not tolerated at any concentration by fish or inverts and a level of 0ppm should be maintained at all times.
Boron (B )
Boron is a very important element, low concentrations can slow down the growth of corals and calcareous algae, whereas high concentration can result in a build up of boric acid, which acts as a bactericide killing essential bacteria. Regular partial water changes will be enough to replace Boron levels in the tank.
Calcium (Ca)
Calcium is a major component of the skeletal material of hard corals, the skeletal needles of soft/leather corals as well as coralline algae and low concentrations will inhibit the growth of these. Because Calcium fulfils important biological functions in a tank like the growth and multiplication of corals, calcareous algae and other organisms it is easily depleted and needs to be constantly replaced. To maintain a stable environment it is important that the calcium content should not fluctuate by more than 15ppm from the optimum range. It is recommended to maintain a Calcium level between 350ppm & 450ppm
Copper (Cu)
Copper is often used as a treatment for parasites and it is essential that the correct concentration is used as high levels can be toxic to marine fish. Copper at any concentration is lethal to invertebrates and therefore is not reef safe. Copper leaches into silicone and blue seals on a tank can be a sign that Copper has been used in it at some point, this Copper can leach back into the tank therefore a tank that has been treated with Copper should not be used for a reef tank. Normal tap water can be naturally high in copper and it is therefore advisable to use purified water (RO/DI) for use in saltwater tanks. A Copper level of 0ppm should be maintained at all times in a reef tank, and between 0ppm & 0.25ppm in a FOWLR
Iodine (I)
Iodine is present in natural sea water at a very low concentration, around 0.06ppm, and occurs in several different forms including iodide, iodate, molecular iodine and hypoiodite. Iodate is the predominant element found in natural sea water and this must be taken into consideration when testing for Iodine. Any test kits not able to detect Iodate will give a false iodine reading, one much lower than what is actually present, so test kits should be capable of measuring all forms of naturally occurring iodine. It is recommended to maintain an Iodine level between 0.06ppm & 0.10ppm in a reef tank, and between 0.04ppm & 0.10ppm in a FOWLR
KH & GK
Calcium is not the only substance needed to form the skeletal material of corals and allow calcareous algae to grow. Carbonates and Bicarbonates are also needed and these two substances can have a major effect on stabilising or buffering pH levels in the aquarium in the correct range of 8.1 to 8.4. The total Carbonate and Bicarbonate concentration is also called Alkalinity or Carbonate Hardness and for a stable system the alkalinity should not fluctuate by more than 5% from the optimum level. It is recommended to maintain an Alkalinity level between 8dKH & 12dKH
Magnesium (Mg)
Magnesium is present in natural sea water in a fairly high concentration, between 1350ppm and 1500ppm, and is an essential element of chlorophyll which is necessary for photosynthesis. Without photosynthesis algae and coral would not be able to produce their own food form light and survive. Magnesium also helps to maintain the correct combination of Calcium concentration and Alkalinity as it slows down the formation of Calcium Carbonate which can absorb many important trace elements within the aquarium. Maintaining a correct Magnesium concentration is therefore very important and is indirectly responsible for fast coral and calcareous algae growth by maintaining correct Calcium and Alkalinity figures. Magnesium is depleted by algae growth and also by the use of excessive Kalkwasser or by exceeding natural Calcium, Alkalinity and pH levels. It is recommended to maintain a Magnesium level between 1250ppm & 1350ppm in a reef tank, and between 1150ppm & 1350ppm in a FOWLR
Nitrate (NO3)
When there are insufficient anaerobic areas in a tank denitrification will not taking place properly and Nitrates will build up. This can also happen in an aquarium where the bioload causes an imbalance, eg. excessive livestock for the aquariums filtration capability or over feeding is occurring. The build up of Nitrates can result in unwanted algae growth and the slowing down of coral growth. It is recommended to maintain a Nitrate level lower than 10ppm in a reef tank, and lower than 30ppm in a FOWLR
Nitrite (NO2)
In a properly cycled aquarium, Nitrite is converted to Nitrate and then this Nitrate is converted into harmless Nitrogen gas or removed with water changes. If this cycle breaks down then Nitrites can build up into high concentrations. Although not as toxic as Ammonia, Nitrite is still lethal to fish and inverts and a level of 0ppm should be maintained at all times.
pH
The pH level in a marine tank has a major impact on many biological processes including the growth of corals and calcareous algae. The pH should not be allowed to fluctuate more than 0.2 units during any 24 hour period and should preferably be kept above 8.2. If the pH is too low then alkalinity may fall and/or a build up of carbon dioxide may arise caused by insufficient aeration. A low pH can be corrected by improving aeration and by increasing the alkalinity using KH + pH buffer additives.
Phosphate (PO4)
If Phosphate is present in high concentrations there may be an increase in growth of undesirable algae and if the level exceeds 0.04ppm the growth rate of corals and calcareous algae may decrease by as much as 90%. Washing frozen foods after thawing can significantly reduce the input of Phosphates and using a high grade, Phosphate free activated carbon can also help to keep Phosphate levels down.
Silica (Si)
Silicates occur in tap water or purified water when the Reverse Osmosis (RO) or De-Ionising (DI) unit is not functioning properly. Silicates can be responsible for diatom blooms and can also block some essential trace elements such as vanadium and molybdenum from being utilised in the tank.
Strontium (Sr)
Strontium plays an important role in accelerating the growth of coral and calcareous algae and natural sea water contains approx. 7ppm to 9ppm. Strontium is very difficult to test for but is usually in balance with calcium levels, therefore if Calcium levels drop Strontium levels will have also. It is recommended to maintain a Strontium level between 8ppm & 14ppm in a reef tank, and between 4ppm & 10ppm in a FOWLR
There are many different types of test kits available from various manafacturers such as Salifert, DelTec, Kent Marine, etc. and all do pretty much the same using the same chemicals. Personal choice plays a part in choosing the right one as does recommendations from other hobbyists. Some people will add lots to their tank, other will add nothing. If it's a small tank then partial water changes with good quality salt will replenish the lost elements quite adequately so the need to dose is minimal unless you have high demand from corals, etc. The most common additives used are Calcium, Iodine and sometimes Magnesium.
Below is a list of the most common elements and compounds found in saltwater tanks along with basic details on their use or effect: (Sources: Salifert, www.liveaquaria.com)
Ammonia (NH3)
Ammonia should be rapidly converted by aerobic nitrification into Nitrite and then Nitrate and finally into Nitrogen gas. It is a highly toxic element produced by fish waste, decomposing organic matter and foods. It is not tolerated at any concentration by fish or inverts and a level of 0ppm should be maintained at all times.
Boron (B )
Boron is a very important element, low concentrations can slow down the growth of corals and calcareous algae, whereas high concentration can result in a build up of boric acid, which acts as a bactericide killing essential bacteria. Regular partial water changes will be enough to replace Boron levels in the tank.
Calcium (Ca)
Calcium is a major component of the skeletal material of hard corals, the skeletal needles of soft/leather corals as well as coralline algae and low concentrations will inhibit the growth of these. Because Calcium fulfils important biological functions in a tank like the growth and multiplication of corals, calcareous algae and other organisms it is easily depleted and needs to be constantly replaced. To maintain a stable environment it is important that the calcium content should not fluctuate by more than 15ppm from the optimum range. It is recommended to maintain a Calcium level between 350ppm & 450ppm
Copper (Cu)
Copper is often used as a treatment for parasites and it is essential that the correct concentration is used as high levels can be toxic to marine fish. Copper at any concentration is lethal to invertebrates and therefore is not reef safe. Copper leaches into silicone and blue seals on a tank can be a sign that Copper has been used in it at some point, this Copper can leach back into the tank therefore a tank that has been treated with Copper should not be used for a reef tank. Normal tap water can be naturally high in copper and it is therefore advisable to use purified water (RO/DI) for use in saltwater tanks. A Copper level of 0ppm should be maintained at all times in a reef tank, and between 0ppm & 0.25ppm in a FOWLR
Iodine (I)
Iodine is present in natural sea water at a very low concentration, around 0.06ppm, and occurs in several different forms including iodide, iodate, molecular iodine and hypoiodite. Iodate is the predominant element found in natural sea water and this must be taken into consideration when testing for Iodine. Any test kits not able to detect Iodate will give a false iodine reading, one much lower than what is actually present, so test kits should be capable of measuring all forms of naturally occurring iodine. It is recommended to maintain an Iodine level between 0.06ppm & 0.10ppm in a reef tank, and between 0.04ppm & 0.10ppm in a FOWLR
KH & GK
Calcium is not the only substance needed to form the skeletal material of corals and allow calcareous algae to grow. Carbonates and Bicarbonates are also needed and these two substances can have a major effect on stabilising or buffering pH levels in the aquarium in the correct range of 8.1 to 8.4. The total Carbonate and Bicarbonate concentration is also called Alkalinity or Carbonate Hardness and for a stable system the alkalinity should not fluctuate by more than 5% from the optimum level. It is recommended to maintain an Alkalinity level between 8dKH & 12dKH
Magnesium (Mg)
Magnesium is present in natural sea water in a fairly high concentration, between 1350ppm and 1500ppm, and is an essential element of chlorophyll which is necessary for photosynthesis. Without photosynthesis algae and coral would not be able to produce their own food form light and survive. Magnesium also helps to maintain the correct combination of Calcium concentration and Alkalinity as it slows down the formation of Calcium Carbonate which can absorb many important trace elements within the aquarium. Maintaining a correct Magnesium concentration is therefore very important and is indirectly responsible for fast coral and calcareous algae growth by maintaining correct Calcium and Alkalinity figures. Magnesium is depleted by algae growth and also by the use of excessive Kalkwasser or by exceeding natural Calcium, Alkalinity and pH levels. It is recommended to maintain a Magnesium level between 1250ppm & 1350ppm in a reef tank, and between 1150ppm & 1350ppm in a FOWLR
Nitrate (NO3)
When there are insufficient anaerobic areas in a tank denitrification will not taking place properly and Nitrates will build up. This can also happen in an aquarium where the bioload causes an imbalance, eg. excessive livestock for the aquariums filtration capability or over feeding is occurring. The build up of Nitrates can result in unwanted algae growth and the slowing down of coral growth. It is recommended to maintain a Nitrate level lower than 10ppm in a reef tank, and lower than 30ppm in a FOWLR
Nitrite (NO2)
In a properly cycled aquarium, Nitrite is converted to Nitrate and then this Nitrate is converted into harmless Nitrogen gas or removed with water changes. If this cycle breaks down then Nitrites can build up into high concentrations. Although not as toxic as Ammonia, Nitrite is still lethal to fish and inverts and a level of 0ppm should be maintained at all times.
pH
The pH level in a marine tank has a major impact on many biological processes including the growth of corals and calcareous algae. The pH should not be allowed to fluctuate more than 0.2 units during any 24 hour period and should preferably be kept above 8.2. If the pH is too low then alkalinity may fall and/or a build up of carbon dioxide may arise caused by insufficient aeration. A low pH can be corrected by improving aeration and by increasing the alkalinity using KH + pH buffer additives.
Phosphate (PO4)
If Phosphate is present in high concentrations there may be an increase in growth of undesirable algae and if the level exceeds 0.04ppm the growth rate of corals and calcareous algae may decrease by as much as 90%. Washing frozen foods after thawing can significantly reduce the input of Phosphates and using a high grade, Phosphate free activated carbon can also help to keep Phosphate levels down.
Silica (Si)
Silicates occur in tap water or purified water when the Reverse Osmosis (RO) or De-Ionising (DI) unit is not functioning properly. Silicates can be responsible for diatom blooms and can also block some essential trace elements such as vanadium and molybdenum from being utilised in the tank.
Strontium (Sr)
Strontium plays an important role in accelerating the growth of coral and calcareous algae and natural sea water contains approx. 7ppm to 9ppm. Strontium is very difficult to test for but is usually in balance with calcium levels, therefore if Calcium levels drop Strontium levels will have also. It is recommended to maintain a Strontium level between 8ppm & 14ppm in a reef tank, and between 4ppm & 10ppm in a FOWLR
There are many different types of test kits available from various manafacturers such as Salifert, DelTec, Kent Marine, etc. and all do pretty much the same using the same chemicals. Personal choice plays a part in choosing the right one as does recommendations from other hobbyists. Some people will add lots to their tank, other will add nothing. If it's a small tank then partial water changes with good quality salt will replenish the lost elements quite adequately so the need to dose is minimal unless you have high demand from corals, etc. The most common additives used are Calcium, Iodine and sometimes Magnesium.
