Algae appear in almost every aquarium, in greater or lesser intensity. These primitive plants spoil the appearance of the tank. Algae grow on glass, plants, roots and stones.
Although there are more than 130000 known types of algae, only a small number of them are likely to show up in your aquarium.
There are several ways to rescue your tank from algae without harming the plants or fishes. In this article, we will look at the most common types of algae.
Key Takeways:
- Algae in aquariums can spoil the tank’s appearance.
- Maintaining the right balance of nutrients and lighting prevents algae growth.
- Plants compete with algae for nutrients.
- Phosphorus levels should be monitored to prevent algae infestation.
- Algae removal methods include biological, chemical, and physical approaches.
- Different types of algae require specific removal and prevention methods.
- Algaecides should be a last resort when other methods fail.
Their small amount proves the right amount of nutrients and applicable lighting. The disturbance of the biological balance creates ideal conditions for the growth of algae.
Plants are the main competitor to algae for access to nutrients. The occurrences of too many micronutrients in relation to the amount needed by plants causes rapid growth of algae.
Phosphorus plays a major role in the infestation of algae. Therefore, it’s important to keep the phosphate in the tank at an appropriately level.
We can divide the fight against algae into biological, chemical and physical methods.
Plants and other organisms need food. The nutrients for plants are:
– nitrogen compounds – in the form of nitrates, nitrites and ammonia. Nitrite and ammonia are especially dangerous for fish. These compounds are formed from food debris, as a result of the decomposition of dead plant parts, and are introduced into the aquarium along with the fish faeces. Use a siphon to clean the gravel.
– carbon dioxide – produced by fish in the process of respiration and the decomposition of organic compounds (faeces, food remains, dead plant parts). In many aquariums, CO2 is a limited gas, therefore it is recommended to additionally fertilize the plants. The best way is perform appropriate CO2 injection. Higher carbon dioxide levels can help you get one step closer to an algae-free tank.
– light – is necessary for the photosynthesis process, but in the tank we should avoid access to sunlight. Artificial lighting will give you control over the light. Sunlight increases the growth of algae.
– micronutrients and macronutrients – including magnesium, potassium, phosphorus
– phosphates – an excess of phosphorus compounds in the water largely contributes to the growth of algae. The concentration of phosphate should be monitored and the appropriate amount should not be exceeded.
What are the main reasons for the growth of algae in the aquarium?
- low amounts of beneficial bacteria in set up tank
- poor water circulation
- low filtration efficiency
- wrong maintenance activities
- too much light
- wrong fertilization of plants – especially with preparations containing a high concentration of phosphorus
- overstocking
- deficient of plants
- too much food
- infrequent water changes
- no constant level of CO2
- exposure to sunlight
- excess phosphorus
An algal bloom is the spontaneous growth of algae in tank. It is a sign that there is too much nutrients in the water. If we don’t take action right away, we may have a big problem.
If you want to decrease the nutrients in your aquarium water, change 15-20 percent of it every week. Scheduled water change is the best way to avoid spontaneous algal growth.
Algae blooms are an inevitable part of the experience of keeping fish, but you can avoid problems by using preventive measures. If nothing helps, we can use algaecides.
Many algaecides are formulated to work against specific types of algae. I recommend using chemicals only as a last resort when other methods have failed.
Knowing how to get rid of algae and keeping it in check is something every beginner should learn.
Brown algae (diatoms)
Brown algae is made of single-celled organism called diatoms and usually appear few weeks after tank starts. Diatoms create a characteristic brown coating on stones and plants.
They are very easy to recognize. Similar to brown algae can look cyabobacteria but the difference is that cyanobacteria has characteristic small bubbles clinging to it.
What causes brown algae (diatoms) in aquarium?
The diatom plague usually go away when the conditions in the tank are stabilized. If this does not happen, we should find the cause of their formation.
Most often it is ineffective biological filtration and insufficient amount of light. It is worth noting that diatoms may thrives in new tanks with bright lights, although they prefer dim lighting. Algae and other forms of algae thrive in tanks with low bacteria counts.
Reasons for the development of diatoms:
- High silicate content in water
- Hard water with a lot of minerals
- Low oxygen content in the water
- Poor filtration and circulation of water
- Insufficient light
- Excess of phosphate and nitrate compounds
How to get rid of brown algae (diatoms)?
The best way to get rid of diatoms is to use several methods at once. First, the lighting intensity should be increased to at least 0.5 W/l. At the same time, the filtration should be increased or the filter should be changed to a more efficient one.
Mechanical removal consists scraping algae from the glass, removing algae from sands or gravel and removing from plants and decor. To clean your glass you can use a scrubbing pad. To get away algae from gravel you should use gravel vacuum.
The best way to get brown algae off other decor or plants is with scrub brush made of metal. You can also use clean toothbrush.
During this time, you should increase the frequency of water changes. You should also monitor the level of nitrates, nitrites and phosphates in the water.
Tap water may contain high levels of nitrates, phosphates and silicates, so it is advisable to invest in a RO unit. The water flowing through the membranes is purified and mineral free.
You should add appropriate minerals to the RO water, which are essential for plants and fish (like calcium and magnesium).
You should also remember to avoid overfeeding. Food debris sinks to the bottom and puts off lots of nitrates and phosphates. Fish that are overfed also excrete more feces, which also translates into higher levels of nitrates and phosphates.
For the fight against diatoms, we can also use Otocinclus sp or Caridina multidentata shrimps, if the water quality is confirm. Removal brown algae by feeding Otocinclus sp or Caridina is also effective.
Some aquarists recommend darkening the tank. This method is not always effective. The effect is usually short-lived and the algae can return with increased force. However, if we decide to use this method, it is worth changing the water regularly, removing diatoms from gravel, and monitoring the water parameters.
A UV sterilizer can be a very good investment. UV rays will kill not only the diatoms, but also algae, bacteria and even viruses. UV can kill all floating diatoms that will not be able to stick and grow on surfaces.
An auxiliary method may be the use of filter media that absorb silicates and phosphates. An example would be media filter with aluminum oxide or a poly-filter that absorbs nitrates, phosphates and some silicates.
The fight against diatoms is not difficult. However, you need to be patient and follow all of the above rules.
Green algae
Chlorophyta spp (GDA – green dust algae)
This type of algae are single-celled green algae. They cover aquarium glass and plants with a thin layer of green dust. They appear in mature tanks as well as in newly established ones. They are often found when digging into the ground.
They can be removed easily just by wiping off or by water movement. It’s common to think of green algae. Many people have no idea that green algae is what they see most of the time in the tank.
What causes green dust algae in aquarium?
Main cause is incorrect ratio of nitrogen and phosphorus in the water. Very common in new setups that are not fully cycled.
How to get rid of green dust algae?
Use an algae scraper to remove green spot algae from the viewing panes. Use gravel vacuum to remove dirt from the gravel then change water.
When you fighting against green algae, it is necessary to take care of a large plant mass in the aquarium.
Do not touch the ground and limit the activities associated with it (tearing out plants or arranging the tank). Fish digging in the ground, for example cory catfish, can contribute to GDA infestation. A UV lamp may also be helpful.
Chlorophyta spp (GSA – Green spot algae)
They create green spots on leaves and glass. It is a multicellular form of green algae. Tiny green spots also appear on slow-growing plants, typically the Anubias-types.
What causes green spot algae in aquarium?
The main cause of this algae is the excess of micronutrients in the water (phosphate depletion) combined with too much lighting.
Remember that it is much easier to overdose microelements in soft water. It is recommended to keep the water hardness at a level not lower than GH=8 and KH=4.
Exposure to sunlight can affect the growth of green spot algae. Also low CO2 and poor fertilization can causes green spot algae in your tank.
How to get rid of green spot algae?
It is relatively difficult to remove from plants. We can use algae scraper to remove green spot algae from glass.
It is worth to perform a water change. During this time, we should stop fertilizing and reducing the amount of light in the tank. Another way is to completely “blackout” the tank for 5-7 days. Liquid Carbo can also be used in the fight against green algae. Look for carbo at your local pet store.
We should remember point green algae often appear with relatively good water parameters and good transparency. Fertilizers should be dosed carefully. We should test the water for phosphatase. A good form of prevention is having green spot algae eaters: sun snails, nerite snails or otocinclus Catfish.
Green Aquarium Water Algae
What causes green aquarium water algae?
The most common cause is poor water circulation, often with an excess of micronutrients in the water. A sudden change in lighting also contributes.
How to get rid of green aquarium water algae?
When green aquarium water appears, you should change 40% of the water in the aquarium. Put filter wool, perlon or non-woven fabric into the filter.
Check that the filter is not clogged. It is worth adding bacteria to the filter media. During the treatment, the lighting should be turned off (you can also perform a 5-7 day blackout).
You should make at least three water changes during this time. We can also use a UV sterilizer.
Algae bloom is also called new tank syndrome. Green Aquarium Water Algae may appear when you put a large number of fish to the tank at the same time. It disturbs the biological balance.
The solution to the situation is to gradually introduce new fish into the aquarium. It’s recommended to dragging the maturation process to 5-6 weeks.
We should avoid overstocking in tank. Incorrect preparation of the substrate (often with the participation of garden soil) also contributes green aquarium water algae.
Green water is easy to eliminate.
OEDOGONIUM Algae (green fuzz algae)
This type of algae are presents as green short, filamentous algae. It most often appears on stones, wood and plants. Filamentous algae look like fuzzy green strands. They are often seen in aquariums that have been existing for a short time.
What causes green fuzz algae in aquarium?
The cause of their formation is not fully understood. It is believed to be a low micronutrients and CO2 in the water. Remember that they also appear in tanks with the correct ratio of elements.
How to get rid of green fuzz algae?
Removed green fuzz algae mechanically. You can use a clean toothbrush. It is worth using Easycarbo, flourish exel or hydrogen peroxide. Some aquarists consider this algae a decoration. The effect is good only when we keep crystal clear water.
To prevent green fuzz algae, periodic testing of water parameters is necessary. You can overdose easycarbo or flourish exel. You can buy them on your local pet store.
Young thallus structures are also a delicacy for some shrimps and fish (Rosy barbs, Amano shrimp, Mollies).
Blue-green algae
Cyanobacteria is not algae but a species of aquatic cyanobacteria that can photosynthesize. In fish keeping, cyanobacteria are conventionally treated as typical algae, even though they are not. They spread over any surfaces in the tank.
Blue-green algae create a thick, smooth, jelly-like carpet that coating all plants and decorations in the tank. In the case of plants, cyanobacteria cut off oxygen to such an extent that they can kill it.
Blue-green algae are accompanied by tiny air-bubbles, which makes them very easy to identify. Cyanobacteria has a specific bad smell. Fish cannot eat cyanobacteria because they are toxic.
What causes blue-green algae (cyanobacteria) in aquarium?
The main cause of blue-green algae is the high phosphate content with small or no nitrate value. An additional factor can also be poor water circulation, insufficient water changes or too much light.
How to get rid of blue-green algae (cyanobacteria)?
The thallus is very easy to remove with your fingers by picking up a large elastic coat. You can wipe them off the plants with your fingers. You can suck up BGA by using vacuum cleaner.
Although it is easy to remove mechanically, it can grow back very quickly (BGA can appear after one day).
After mechanical removal of cyanobacteria (the more the better), 50% of the water should be changed.
During this time, you should raise nitrogen levels and stop using fertilizers containing phosphorus. Using tap water for changes may contribute to the recurrence of cyanobacteria. Use RO water.
It is worth using a fine-mesh filter made of pearl wool. Even the smallest impurities will be removed. Filter should be cleaned every two days. You can also blackout your fish tank for few days.
How to avoid harmful cyanobacteria?
In order to prevent cyanobacteria, nitrogen and phosphorus levels in the water should be monitored. In the event of their occurrence, we don’t add phosphorus, but we add nitrogen to the water.
Take care of the right water circulation and amount of light. Fast-growing plants can also blocking the growth of cyanobacteria.
It’s important to check your plants regularly to avoid having algae grow on them. Algae should be removed as soon as possible. Don’t let it spread to other parts of your tank.
Rhizoclonium algae
This type of algae forms pale green hair-like strands. They most often occur in places with poor water flow (e.g. in thickets of plants).
What causes rhizoclonium algae in aquarium?
The main cause is an excess of iron in the water combined with strong lighting and poor water circulation. It can also be low levels of CO2 and nutrients.
How to get rid of rhizoclonium algae?
Individual tufts can be removed with tweezers. Water circulation should be increased. During this time, you should not change the water and fertilize. This algae feeds some herbivorous shrimps and snails. The addition of Carbo (overdose the tank with EasyCarbo) to the water gives good results.
How to prevent rhizoclonium algae?
Prevention consists in cyclical water changes and control of water parameters. We should not exceed the level of fertilizers. It is worth decontaminating the water prophylactically with carbo or potassium permanganate. Also pay attention to the circulation of water in the tank.
Red Algae (Rhodophyta)
This type of algae are forming thick patches, usually up to 5 mm long, that resemble a beard. They are several red algae species, most commonly seen in freshwater aquarium is black beard algae (BBA).
Red algae can take on different colors (usually red, brindle or brown, sometimes even black). They cover plants, stones, roots, aquarium equipment and not often the glass of the tank.
It grows in small clumps with a dense structure. Brush forms like the movement of water, which is why they often start to appear at the outlet of the filter.
What causes red algae in aquarium?
Red algae grows best in hard water. They like places where there is a strong flow of water. The main reason for their formation is the generally imbalance of nutrients (typically in a new setup).
It may be related to the accumulation of organic compounds in the substrate. There are more causes which may affect their appearance. These are low CO2, to much light or exposure to sunlight, phosphorus depletion.
How to get rid of red algae?
Removing red algae is very difficult. Mechanical removal is ineffective. We can use algae scrapper to remove as much as you can. Leaves covered with red algae should be removed.
The best way is overdosing the tank with Carbo or soda water. The next day after application, we should change water. This activity we should repeated several times (Carbo + water change, carbo + water change). During this time, we should stop fertilizing.
How to avoid red algae?
Water changes will result to reduce the amount of phosphate. However, the level of nitrates should be controlled, as their lack will result in algal growth. Siamese Algae Eaters feed on red algae, so it is worth having them in the aquarium. Algae are also eaten by florida flag fish and amano shrimp.
SPIROGYRA
Spirogyra creates thin, twisted strands (narrower than human hair). They are very strong. When you try to burst them, they make a characteristic shooting sound. Spirogyra is built from spiral-shaped chloroplast.
What causes spirogyra in aquarium?
The causes of the occurrence are not fully known. It is mainly caused by incorrect concentrations of micronutrients, inadequate filtration and water changes. Spirogyra growth is correlated with a high concentration of ammonia.
How to get rid of spirogyra?
They can be removed mechanically. In this case, we use tweezers on which we wind threads of algae. Due to its hardness, no fish eat this algae.
Check the water parameters regularly. It is worth increasing the water changes and giving Carbo. You can also blackout your tank with CO2 turned off.
How to prevent spirogyra?
There is no known effective prevention. Check the water parameters and change the water regularly. Remove dead livestock, avoid overfeeding and occasionally dose the tank with EasyCarbo, Ecel or TNC Carbon.
In conclusion
It’s easy to prevent algal growth in a aquarium, but it takes time and effort to maintain the health of a freshwater aquarium. You need to monitor the light levels, nutrient levels, and water conditions in your tank. Preventive measures are the best treatment to avoid algal bloom in fish tank.
It is my pleasure to have assisted you in identifying the types of algae and the best methods of removal, so that you might not make the same mistakes I did.
