While most hobbyists first encounters with algae is in dealing with how to control or erradicate them from their aquariums, there are also many of us who are now keeping many of the macro (large) algae species as part of their system's landscape, of which only increases the biodiversity of such systems and is a great help in maintaining the balance between nutrient imports and exports.
Since it would be of higher interest to those trying to deal with problems in algae control, I will try to provide the information and links that I have found to be of use in this area first.
A check list of what you can do to deny problem algae and cyano bacteria the conditions they need to thrive.
1. First, understand that algae and cyano bacterias will always be a part of your system, there is no way you will ever eradicate it totaly. Having to clean an algae film from your aquarium's glass every few days and keeping a few herbivores such as snails, is just part of keeping any type of aquarium. But when algae dominates your system and threatens to outcompete and smother your corals, action must be taken.
(A) We must also realize that a new setup is going to take time for its biology to get established and for any controls to take effect. Six months to a year is not an unreasonable amount of time for a system to balance out. Remember, this is a hobby that demands patience.
(B) The entire battle that is fought with any algae or bacterial problems can be traced back to being an issue of nutrients.
2. Your freshwater sources : Starting out with and continuing to use as pure a freshwater source as possible is probably the single best thing that you can do to tip the odds in your favor. Tap water is usualy loaded with impurities and nutrients that will fuel excessive algae growth. As such, I believe that one of the first peices of equipment that you should purchase is an RO/DI water filtration system, if that is not possible right away, then at least use distilled water when making up your saltwater.
3. Water changes : As an old saying goes within this hobby, " the solution to pollution is dillution". Doing frequent large water changes is, in my opinion, THE single best thing you can do for your entire system. Not only are you removing (dilluting) out nutrients, you are also removing a host of other elements that will build up in an enclosed system while at the same time, bringing other much needed and used elements back up to proper levels without having to become a chemistry major and doing what I feel is the single biggest mistake made in this hobby, which is adding additives and supplements.
4. Limit the nutrients you add to the tank : Everything you feed the tank wether its "bad" water, supplements or fish/coral food will add to the importation of nutrients, which will then be used by algae.
(A) Limit or stop using flake or pelleted foods which contain high levels of phosphates and other excessive nutrients. Frozen prepared foods or fresh seafoods are a much better choice.
(B) Do not add Iodine supplementation. The only "fact" that has been proven is that algae consumes and holds a great quantity of this element. All of the claims of invertebrates or corals needing amounts greater than found in natural sea water are ancedotal and have yet to be proven. If you want alot of algae, add Iodine.
5. Examine your stocking levels of fish. Quite often an aquarium will be overstocked with fish that the system's biology can not deal with. Fish being the greatest source of nutrient importation by their just being alive and our having to feed them.
6. If you can not beat them, then join them : Using algae itself to uptake and lock up nutrients is a highly effective and much more natural method of nutrient control. Having a sump compartment or another tank used to cultivate algae which can then be trimmed and thrown away will help to deny those algae in the show tank the nutrients they need to grow.
7. Use herbivores such as snails to consume that algae which will grow within the show tank.
The following links will be of use and interest regarding algae and cyanobacteria control.
Reef Aquria as Ecosystems - "Discussing marine reef aquaria as ecosystems and how we should manage them using an ecosystem or holistic approach, as opposed to the micromanagement philosophy that seems inherent in most reef aquarium husbandry."
The types of algae in marine aquria - "Pond scum, kelp, red tides, seaweed and "that film on the glass". These are but a few of the many names that are used to describe the algae. These are the plants of the sea. It is a huge assemblage of organisms with species numbering in the tens of thousands."
Algae Control Tips - "A selection of useful tidbits of information and tricks for the marine aquarist submitted by Advanced Aquarist's readership"
Nuisance Algae in the Reef Aquarium - "In this series of articles I will explain the different types of fuel that allow these unsightly algae to take over an aquarium."
Clean up Crews - "What I intend for this article is to give some general ideas to the various "clean-up crew" participants that are available and their usefulness to the marine aquarium."
Use of Mangroves - "Mangroves have become increasingly familiar additions to marine displays and refugia"
Dinoflagellates - "Many dinoflagellates are photosynthetic and are among the major primary producers of the phytoplankton along with diatoms."
Diatoms & Silica - "Silica is a chemical that is feared by many reef keepers. Visions of a reef tank covered with diatoms so thick that you can not see through the glass come to mind."
Cyanobacteria webserver - "Cyanosite is dedicated to the information transfer within the cyanobacterial research community"
In our battle with the micro or nuisance algae, you will find many references to using macro (large) algae as a means to export nutrients that fuel the algae types that we need to control. What is usualy over looked is the fact that many of the larger algae are quite pleasant to look at and provide a much more natural landscape, such can be said of the sea grasses as well. The following links will relate to their identification and care tips.
Caulerpa Algae - It is quite common within the hobby to use any number of Caulerpa algae species as a means to control nutrient levels within our reef aquariums. Given that this group of algae only do well with higher nutrient levels than what we strive to maintain within our systems, I would only recommend their use for those aquariums that constantly struggle with higher than normal nutrient levels. There are a few dangers or concerns to be aware of if this algae group is kept.
- Caulerpa species are fast growers, and do so with strong holdfasts that anchor the algae to the substrates making them difficult to remove. Even with their removal, any remaining holdfasts on the substrate can regenerate and make these species difficult to be rid of once established. If you do wish to keep these alage, I would do so outside of the main display aquarium within a refugium.
- With the fast growth, comes faster nutrient uptake, which is what we would want when struggling with water quality issues brought on by excessive nutrients. The problem with the use of these species is that they are found in the wild only in near shore areas that contain higher nutrient levels than that found out on the coral reef. When the nutrient levels fall, the algae will suffer and most likely go into sporalation (method of reproduction), This is characterized by the algae becoming translucent and disintegrating, this can happen very quickly. When it does happen, if enough of the algae is present it can foul the water and result in mass die off. As such, I would only use these species temporarily to get excessive nutrients under control (water changes would be more effective) and then switch to other macro algae species of which the majority of them require lower nutrient levels to live in than the caulerpa species.
- Caulerpa species also contains a toxin called caulerpenyne which makes it undesireable to most herbivores, the toxin is also released anytime the algae is broken and possibly just leached from the algae as it grows. The toxin can over long term exposure or with high amounts have deleterious effects on inverts and fish. The toxin can be removed with the use of activated carbon, and I would suggest if you intend to keep the caulerpa then you should use activated carbon somewhere in the system.
As you can see, the use of any of the Caulerpa algae would most likely not be a good idea as there are better and safer alternatives to bringing high nutrient levels under control in my opinion. If you do keep these algae, I would be aware that as your aquarium's nutrient levels start to fall, you risk having it suddenely die off. Not a good thing to have happen. Algae in the coral reef envrionment - "Competition for space with other attached organisms is one of the main factors controlling growth of the marine flora."
Beyond the Refugium, A macroalgae primer - "This series will focus on algal marine plants and attempt to highlight their more desirable and beautiful attributes."
A Planted Aquarium - "Seagrasses, until recently, had earned only an obscure place in marine aquaria as occasional, short lived accents in full blown reef tanks or as nutrient export plants in refugiums."
Macroalgae for landscaping - "A very well put together guide"
The SeaPlants Handbook - A very comprehensive site and a great resource for algae identification.
Algae Identification - "This is basically a "visual" page where photos of different forms of algae and possible biological control critters can be seen."
Calurpa Sporulation - "I'm sure most hobbyists that have kept Caulerpa in their refugium or display tank know about or have experienced this algae's reproductive activity."
Since life on this planet would not be possible without them, including within our aquariums, I feel that we should take some time to get to know at least a few of the bacterial families that are of concern to our aquarium's biology. Knowing what certain strains need provides us with the knowledge on how to either control them, or promote them.
Bacterial Diversity Study Guide - Get to know our friends and our enemies.
Bacteria - Wikipedia's very informative article and the source of the following information.
CyanoBacteria Link #2 Link #3 - "Though cyanobacteria do not have a great diversity of form, and though they are microscopic, they are rich in chemical diversity."
A note on the "red slime removers" - Being that the cyanobacteria are just that, bacteria. Such products use an antibacterial medication to kill off the cyanobacteria. To me, this should only be done as a last resort and not something to rely upon on a regular basis. If the problem is so great that all your efforts to be rid of it fails, then I would consider killing it not with any of the products available, but by simply using the main ingredient those products contain, which is listed below. Of course such treatment should only be done when the cyanobacteria's food source(s) are limited and controlled.
Such products usualy contain either Erythormycin (white in coloration) or Tetracycline (yellow in coloration). Also note that the product "ChemiClean" contains Erythromycin.
Most bacteria may be placed into one of three groups based on their response to gaseous oxygen. Aerobic bacteria thrive in the presence of oxygen and require it for their continued growth and existence. Other bacteria are anaerobic, and cannot tolerate gaseous oxygen, such as those bacteria which live in deep underwater sediments. The third group are the facultative anaerobes, which prefer growing in the presence of oxygen, but can continue to grow without it.
Bacteria may also be classified both by the mode by which they obtain their energy. Classified by the source of their energy, bacteria fall into two categories: heterotrophs and autotrophs. Heterotrophs derive energy from breaking down complex organic compounds that they must take in from the environment -- this includes saprobic bacteria found in decaying material, as well as those that rely on fermentation or respiration.
The other group, the autotrophs, fix carbon dioxide to make their own food source; this may be fueled by light energy (photoautotrophic), or by oxidation of nitrogen, sulfur, or other elements (chemoautotrophic). While chemoautotrophs are uncommon, photoautotrophs are common and quite diverse. They include the cyanobacteria, green sulfur bacteria, purple sulfur bacteria, and purple nonsulfur bacteria. The sulfur bacteria are particularly interesting, since they use hydrogen sulfide as hydrogen donor, instead of water like most other photosynthetic organisms, including cyanobacteria.
How Bacteria Eat: Like all living organisms bacteria need to eat in order to live, grow and reproduce. However, bacteria are far too small to have a mouth. Instead they have special channels in their cell walls and cell membranes which allow, or even assist some molecules to cross. Once the molecules are inside the cell they can be broken down into their componant parts before being rebuilt into the macromoloecules the bacteria needs in order to build and repair itself, or generate energy.
Unfortunately for the bacteria the surrounding environment is not always full of free-floating molecules of the correct sort. Instead, the molecules may be all bound together. To solve this problem bacteria have evolved the habit of leaking enzymes out into the environment around them. These enzymes then do what ever it is they do, attack specific tissues and molecules (proteases attack proteins, cellulases attack cellulose etc) and break them up into smaller units. Eventually molecules of a size that the bacteria can take into itself are made that the cell can then absorb through the channels mentioned above.
Bacterial metabolism is classified on the basis of three major criteria: the kind of energy used for growth, the source of carbon, and the electron donors used for growth. An additional criterion of respiratory microorganisms are the electron acceptors used for aerobic or anaerobic respiration.
Cellular respiration describes the metabolism reactions and processes that take place in a cell to obtain biochemical energy from fuel molecules and the release of the cells' waste products. Energy is released by the oxidation of fuel molecules and is stored as "high-energy" carriers. The reactions involved in respiration are catabolic reactions in metabolism.
Fuel molecules commonly used by cells in respiration include glucose, amino acids and fatty acids, and a common oxidizing agent (electron acceptor) is molecular oxygen (O2). There are organisms, however, that can respire using other organic molecules as electron acceptors instead of oxygen. Organisms that use oxygen as a final electron acceptor in respiration are described as aerobic, while those that do not are referred to as anaerobic.
The energy released in respiration is used to synthesize molecules that act as a chemical storage of this energy. One of the most widely used compounds in a cell is adenosine triphosphate (ATP) and its stored chemical energy can be used for many processes requiring energy, including biosynthesis, locomotion or transportation of molecules across cell membranes. Because of its ubiquitous nature, ATP is also known as the "universal energy currency", since the amount of it in a cell indicates how much energy is available for energy-consuming processes.
Nitrification is the biological oxidation of ammonia with oxygen into nitrite followed by the oxidation of these nitrites into nitrates. Nitrification is an important step in the nitrogen cycle in water. The oxidation of ammonia into nitrite, and the subsequent oxidation to nitrate is performed by two different bacteria (nitrifying bacteria). The first step is done by bacteria of the genus Nitrosomonas and Nitrosococcus. The second step (oxidation of nitrite into nitrate) is done by bacteria of the genus Nitrobacter, with both steps producing energy to be coupled to ATP synthesis.
Denitrification is the process of reducing nitrate and nitrite, highly oxidised forms of nitrogen available for consumption by many groups of organisms, into gaseous nitrogen, which is far less accessible to life forms. Denitrification takes place under special conditions in marine ecosystems. In general, it occurs when oxygen (which is a more favourable electron acceptor) is depleted, and bacteria turn to nitrate in order to respire organic matter. Because our water is rich with oxygen, denitrification only takes place in areas such as our sandbeds where oxygen is very limited.
Denitrification proceeds through some combination of the following steps:
nitrate → nitrite → nitric oxide → nitrous oxide → dinitrogen gas
Used by permission. Many thanks to Charlies and Linda Raabe for their support. www.chucksaddiction.com