Although algae have some capability to alter the quality of the water that surrounds them, they are also strongly affected by the water chemistry.
SALINITY - Algae may adapt to a wide range of salinity. Many species do not tolerate a large sudden change in salinity. The nuisance algae for the most part are not amoung the intolerant algae. For some varieties of cyanobacteria a sudden drop or increase in salinity may resolve a problem bloom, but for most it does not and filamentous green and red algae tolerate salinity changes quite well. Caulerpa species, however, do not tolerate wide fluctuations in salinity and it might be possible to eleminate a problem species on rocks by removing the affected rocks and exposing them to a specific gravity change of .010 points difference in a holding tank. Maintain this specific gravity for a few hours before replacing the rocks back into the main tank. This salinity change will also kill many coraline algae, as well as sponges on the live rocks.
ALKALINITY - High alkalinity promotes calcification and this encourages the rapid growth of calcifying algae such as red coralline algae and green Halimeda spp. High alkalinity combined with calcium dosing promotes the precipitation of phosphate and this limits algae growth.
CARBON - Carbon may be derived from carbon dioxide, carbonates, bicarbonates, or organic compounds. Carbon dixoide is present in various forms in water. Below Ph 5, co2 is the main species, between 7 - 9 bicarbonate is the most present and above Ph 9.5 carbonate begins to dominate. Above Ph 9 calcium carbonate precipitates.
CARBON DIOXIDE - Carbon dioxide is a fertilizer for plants, being an essentiaol component of the photosynthesis process. Dissoved carbon dioxide occurs as carbonic acid and its presence in water lowers the Ph. During the day when plants are illuminated and photosynthesis is occurring the dissoved co2 is taken up from the water and the Ph rises. At night when no photosynthesis is taking place and the co2 builds up thereby contributing to a falling Ph.
ENRICHED AIR - Standard indoor home aquarium designs have the aquarium exchanging gasses with the air in the room where they are located. If the room is small and does not have rapid ventilation with the outdoors the air quality could be quite different than the outdoors. People contribute to the co2 level of a room. The more people in the room the lower the Ph will be in the aquarium. If the room where the aquarium is located has poor air exchange and a chornically high population of people the effect can promote the growth of algae, given the presence of other fertilizers such as phosphate, ammonium, and iron.
PHOSPHORUS - Algae utilize inorganic phosphorum in the form of orthophosphate. Algae hydrolyse the organic phosphates and liberate the usable inorganic orthophosphate. Algae also accumulate phosphate beyond their immediate nutritional needs. The store the excess phosphate as polyphosphate in the form of granules in the cytoplasm. Under phosphate limited conditions they not only use up their stores, they also increase the activity of phosphatase enzymes to obtain phosphate from as many sources as possible. Some algae live in association with bacteria that liberate phosphate from the substrates on which the algae and bacteria are growing.
PHOSPHATE AND KALKWASSER DOSING - Kalkwasser as top off water supplies calcium ions for coral growth and precipitates phosphate from the water when it is added.
DISSOLUTION OF PHOSPHATE - When phosphate precipitates as calcium phosphate it is insoluble at typical aquarium Ph. It may accumulate heavily in the bottom substrait and in live rocks. The dissolution of calcium phosphate requries a sufficiently low Ph that effectively does not occur in aquariums. One way that precipitated phosphate can be made available is if the substrate is used in a calcium reactor that utilizes caron dioxide to lower the Ph and dissolve the substrate. Much of this phosphate spontaneously precipitates as calcium phosphate again when it enters the aquarium that has a high Ph and an abundance of calcium ions. Some may however be available and promote algae growth.
NITROGEN - Most algae use nitrate, nitrite, or ammonium as sources of nitrogen. Ammonium is preferred over nitrate and concentrations of ammonium above 1 micromol/liter may inhibit uptake of nitrate by some algae. Algae are also able to utilize a wide variety of organic sources of nitrogen such as urea. Nitrates accumulate in the vacuoles of marine algae. Derbesia may have nitrate levels 500 times natural seawater and valonia 2000 times natural seawater level. Although marine algae generally prefer to use nitrogen in the form of ammonium, nitrate is a food for algae and its presence in the aquarium water can stimulate algae growth.
SOURCES OF NITRATE - The principle sources of nitrogen in aquariums are food additions for the fishes. Dry foods have a high protien content and provide a high concentration of nitrogen. The fish, invertevrates, and microorganisms that eat these proteins and amino acids produce nitrogen rich waste ammonium. Since algae will consume ammonium before bacteria convert it to nitrate, algae growing in the aquarium tend to limit the formation of nitrate by bacteria.
CYANOBACTERIA FIX NITROGEN - Cyanobacteria are able to collect dissoved atmoshperic nitrogen and store it in their tissues. When they die and decompose or when they are eaten by herbivores this stored nitrogen returns to the water as ammonium, supplying food to other algae. In this way an aquarium with no fish and no food additions can with a population of cyanobacteria and an aerobic biological filter develope high levels of nitrate accumulation.
SILICATES - Diatoms use silicate in the form of orthosilicic acid to form their siliceous skeletons. The concentration of silicate - silica in natural seawater ranges from a trace to as much as 4 mg/l. Based on 50 ppm silicate in water to be filtered by ro system, the result after filtration would be 5ppm. A secondary deionization filter placed after the ro filter would bring the silicate down to .5 ppm which is an acceptable level for top off water. So, it is important to know the level of silicate in your tap or unfiltered water. Silica is only slightly soluble in seawater and its cycle in nature is limited such that diatoms that use it are basically insoluble except under very alkaline situations. So, diatom growth slows with time as an aquarium ages. a large water change, which may significantly elevate the silicate level, could produce a short term bloom of diatom growth usually appearing as a brown coat on the glass a day or so after the water change and lasting for about a week.
Magnesium - Magnesium is a component of the pigment chlorphyll. It is required for all pigmented algae. Magnesium is unlikely to be a factor limiting the growth of algae in seawater aquariums due to its high concentration in seawater, however, the use of magnesium by coralline algae, which deposit it along with calcium carbonate in their skeletons contain from 7 to 30% magnesium carbonate. Reports exist of die off of coralline algae due to magnesium levels in the aquarium being well below natural seawater values (apprx. 1300 ppm at a specific gravity of 1.025). Remember that natural seawater values are measured at a specific gravity of 1.025. you must adjust for lower or higher salinities. So if you had a salinity of 1.023 a magnesium level below 1300 ppm may not be a sign of deficiency.
CALCIUM - Calcium is requried by many algae, generally in small amounts, much less than is available in seawater. Calcifying algae such as Halimeda or red coralline algae take up larger quantities of calcium from the water.
POTASSIUM - Required for all algae tested.
TRACE ELEMENTS - Trace elements such as iron, manganese, molybdenum, cobalt, and zinc are known to enhance algae growth. There are not specific levels indicated only that they are available in the water collum.
MOLYBDENUM - Nitrogen fixation by blue green algae requies molybdenum.
IRON - Iron is a critical requriement for algae. Iron deficiency lowers the rate of photosynthesis.
MANGANESE - Manganese is involved in nitrogen metabolism and is believed to stimulate photsynthesis and growth. Manganese is requreid by some algae for growth in the light and may also be requried by zooxanthellae. Manganese is often limited in marine aquariums and should be added via supplements.
BORON - Boron deficiency may cause pigment loss in certain algae. Borate is included in many commercial buffers (often in excess) and in some trace element supplementations.
VITAMINS - The addition of vitamin supplements to the aquarium water should be done sparingly as it may promote excessive growth of some algae. Generally it is best to reserve the use of supplements to soaking foods in them for the purpose of enhancing the food nutritional value just before feeding them to fishes or invertebrates.
DISSOLVED ORGANIC SUBSTANCES - besides vitamins other dissoved organic substances such as acetate, sugars, and various amino acids may stimulate excessive growth of agae.
THE ABOVE ARE EXERTS FROM THE BOOK ALGAE a problem solver guide by Julian Sprung/distributed by two little fishies/ ISBN 1-883693-02-0
FOR THOES THAT NEED A MORE INDEPTH INFORMATION BASE ON ALGAE I STRONGLY RECOMMEND THE ABOVE BOOK WHICH CONTAINS MUCH MORE INFORMATION, PROBLEM SOLVING, ETC.
SALINITY - Algae may adapt to a wide range of salinity. Many species do not tolerate a large sudden change in salinity. The nuisance algae for the most part are not amoung the intolerant algae. For some varieties of cyanobacteria a sudden drop or increase in salinity may resolve a problem bloom, but for most it does not and filamentous green and red algae tolerate salinity changes quite well. Caulerpa species, however, do not tolerate wide fluctuations in salinity and it might be possible to eleminate a problem species on rocks by removing the affected rocks and exposing them to a specific gravity change of .010 points difference in a holding tank. Maintain this specific gravity for a few hours before replacing the rocks back into the main tank. This salinity change will also kill many coraline algae, as well as sponges on the live rocks.
ALKALINITY - High alkalinity promotes calcification and this encourages the rapid growth of calcifying algae such as red coralline algae and green Halimeda spp. High alkalinity combined with calcium dosing promotes the precipitation of phosphate and this limits algae growth.
CARBON - Carbon may be derived from carbon dioxide, carbonates, bicarbonates, or organic compounds. Carbon dixoide is present in various forms in water. Below Ph 5, co2 is the main species, between 7 - 9 bicarbonate is the most present and above Ph 9.5 carbonate begins to dominate. Above Ph 9 calcium carbonate precipitates.
CARBON DIOXIDE - Carbon dioxide is a fertilizer for plants, being an essentiaol component of the photosynthesis process. Dissoved carbon dioxide occurs as carbonic acid and its presence in water lowers the Ph. During the day when plants are illuminated and photosynthesis is occurring the dissoved co2 is taken up from the water and the Ph rises. At night when no photosynthesis is taking place and the co2 builds up thereby contributing to a falling Ph.
ENRICHED AIR - Standard indoor home aquarium designs have the aquarium exchanging gasses with the air in the room where they are located. If the room is small and does not have rapid ventilation with the outdoors the air quality could be quite different than the outdoors. People contribute to the co2 level of a room. The more people in the room the lower the Ph will be in the aquarium. If the room where the aquarium is located has poor air exchange and a chornically high population of people the effect can promote the growth of algae, given the presence of other fertilizers such as phosphate, ammonium, and iron.
PHOSPHORUS - Algae utilize inorganic phosphorum in the form of orthophosphate. Algae hydrolyse the organic phosphates and liberate the usable inorganic orthophosphate. Algae also accumulate phosphate beyond their immediate nutritional needs. The store the excess phosphate as polyphosphate in the form of granules in the cytoplasm. Under phosphate limited conditions they not only use up their stores, they also increase the activity of phosphatase enzymes to obtain phosphate from as many sources as possible. Some algae live in association with bacteria that liberate phosphate from the substrates on which the algae and bacteria are growing.
PHOSPHATE AND KALKWASSER DOSING - Kalkwasser as top off water supplies calcium ions for coral growth and precipitates phosphate from the water when it is added.
DISSOLUTION OF PHOSPHATE - When phosphate precipitates as calcium phosphate it is insoluble at typical aquarium Ph. It may accumulate heavily in the bottom substrait and in live rocks. The dissolution of calcium phosphate requries a sufficiently low Ph that effectively does not occur in aquariums. One way that precipitated phosphate can be made available is if the substrate is used in a calcium reactor that utilizes caron dioxide to lower the Ph and dissolve the substrate. Much of this phosphate spontaneously precipitates as calcium phosphate again when it enters the aquarium that has a high Ph and an abundance of calcium ions. Some may however be available and promote algae growth.
NITROGEN - Most algae use nitrate, nitrite, or ammonium as sources of nitrogen. Ammonium is preferred over nitrate and concentrations of ammonium above 1 micromol/liter may inhibit uptake of nitrate by some algae. Algae are also able to utilize a wide variety of organic sources of nitrogen such as urea. Nitrates accumulate in the vacuoles of marine algae. Derbesia may have nitrate levels 500 times natural seawater and valonia 2000 times natural seawater level. Although marine algae generally prefer to use nitrogen in the form of ammonium, nitrate is a food for algae and its presence in the aquarium water can stimulate algae growth.
SOURCES OF NITRATE - The principle sources of nitrogen in aquariums are food additions for the fishes. Dry foods have a high protien content and provide a high concentration of nitrogen. The fish, invertevrates, and microorganisms that eat these proteins and amino acids produce nitrogen rich waste ammonium. Since algae will consume ammonium before bacteria convert it to nitrate, algae growing in the aquarium tend to limit the formation of nitrate by bacteria.
CYANOBACTERIA FIX NITROGEN - Cyanobacteria are able to collect dissoved atmoshperic nitrogen and store it in their tissues. When they die and decompose or when they are eaten by herbivores this stored nitrogen returns to the water as ammonium, supplying food to other algae. In this way an aquarium with no fish and no food additions can with a population of cyanobacteria and an aerobic biological filter develope high levels of nitrate accumulation.
SILICATES - Diatoms use silicate in the form of orthosilicic acid to form their siliceous skeletons. The concentration of silicate - silica in natural seawater ranges from a trace to as much as 4 mg/l. Based on 50 ppm silicate in water to be filtered by ro system, the result after filtration would be 5ppm. A secondary deionization filter placed after the ro filter would bring the silicate down to .5 ppm which is an acceptable level for top off water. So, it is important to know the level of silicate in your tap or unfiltered water. Silica is only slightly soluble in seawater and its cycle in nature is limited such that diatoms that use it are basically insoluble except under very alkaline situations. So, diatom growth slows with time as an aquarium ages. a large water change, which may significantly elevate the silicate level, could produce a short term bloom of diatom growth usually appearing as a brown coat on the glass a day or so after the water change and lasting for about a week.
Magnesium - Magnesium is a component of the pigment chlorphyll. It is required for all pigmented algae. Magnesium is unlikely to be a factor limiting the growth of algae in seawater aquariums due to its high concentration in seawater, however, the use of magnesium by coralline algae, which deposit it along with calcium carbonate in their skeletons contain from 7 to 30% magnesium carbonate. Reports exist of die off of coralline algae due to magnesium levels in the aquarium being well below natural seawater values (apprx. 1300 ppm at a specific gravity of 1.025). Remember that natural seawater values are measured at a specific gravity of 1.025. you must adjust for lower or higher salinities. So if you had a salinity of 1.023 a magnesium level below 1300 ppm may not be a sign of deficiency.
CALCIUM - Calcium is requried by many algae, generally in small amounts, much less than is available in seawater. Calcifying algae such as Halimeda or red coralline algae take up larger quantities of calcium from the water.
POTASSIUM - Required for all algae tested.
TRACE ELEMENTS - Trace elements such as iron, manganese, molybdenum, cobalt, and zinc are known to enhance algae growth. There are not specific levels indicated only that they are available in the water collum.
MOLYBDENUM - Nitrogen fixation by blue green algae requies molybdenum.
IRON - Iron is a critical requriement for algae. Iron deficiency lowers the rate of photosynthesis.
MANGANESE - Manganese is involved in nitrogen metabolism and is believed to stimulate photsynthesis and growth. Manganese is requreid by some algae for growth in the light and may also be requried by zooxanthellae. Manganese is often limited in marine aquariums and should be added via supplements.
BORON - Boron deficiency may cause pigment loss in certain algae. Borate is included in many commercial buffers (often in excess) and in some trace element supplementations.
VITAMINS - The addition of vitamin supplements to the aquarium water should be done sparingly as it may promote excessive growth of some algae. Generally it is best to reserve the use of supplements to soaking foods in them for the purpose of enhancing the food nutritional value just before feeding them to fishes or invertebrates.
DISSOLVED ORGANIC SUBSTANCES - besides vitamins other dissoved organic substances such as acetate, sugars, and various amino acids may stimulate excessive growth of agae.
THE ABOVE ARE EXERTS FROM THE BOOK ALGAE a problem solver guide by Julian Sprung/distributed by two little fishies/ ISBN 1-883693-02-0
FOR THOES THAT NEED A MORE INDEPTH INFORMATION BASE ON ALGAE I STRONGLY RECOMMEND THE ABOVE BOOK WHICH CONTAINS MUCH MORE INFORMATION, PROBLEM SOLVING, ETC.
