Brown algae is a form of algae called diatoms that can photosynthesise as well as eating chemicals in the water. So they can survive even in low light levels as long as their alternative food sources are available. Silicate, phosphorus and nitrates in the water are potential food sources for them.
Recognising brown algae.
When you see a light to dark brown blotches which appear as a slimy film covering any aquarium surface then you are highly likely to have brown algae. It is easily displaced from any surface and can be vaccuumed off glass, plants and gravel.
What causes brown algae?
It usually comes about when there is low light levels, low green algae or plant growth and when there is an abundance of silicate, nitrate or phosphorus in the aquarium. This usually happens in a new aquarium. The silicate can come from the glass of a new aquarium leaching silicate into the water or from newly used sand leaching silicate. Sometimes the rocks in the aquarium contain minerals that feed brown algae so may need removing.
Is brown algae harmful?
It can be harmful to plants or corals because it can coat them and block sunlight and nutrients to them. It the algae starts to die it can cause pollution problems. However, many algae eating fish will relish brown algae and is generally not harmful if it doesn’t overly cover plants or corals.
How can you cure brown algae?
The best way is to deprive the algae of the nutrients that the it feeds off. Correct the lighting problem, such as buying a new light if your aquarium bulb is old or buy a brighter light. The algae will take up the nutrients from the newly set up tank. Once the tank has matured the algae should run out of food.
The second way to cure brown algae is to continually scrape it and syphon it from the aquarium. The nutrients locked inside the brown algae will also be removed along with it. When you scrape off the algae make sure it is removed from the water. If it is allowed to remain in the water it will simply re-attach elsewhere or it might die and leave silicate in the aquarium water, so will re-appear. If the water you are using contains silicates and phosphorous then you might either need to put silicate/phosphorus remover in your aquarium or you could try mixing tap water with reverse osmosis water.
Removing any suspect rocks or gravel in the aquarium and replacing with safer gravels without silicates or phosphorus. Sometimes all it takes is to wait for the aquarium to cycle and mature. The brown algae usually gets overtaken by green algae.
Add a couple of otocinclus catfish which will devour it. In a saltwater tank fish like yellow tangs like to eat it too.
I suggest you avoid any chemical treatments to kill off the brown algae because of the side effects on your other tank inhabitants and the harmful effect on the biological filter.
Preventing brown algae.
Use good lighting. Set up fast growing plants. Use safe gravel or aged sand. Check out the mineral content of your rocks. Do not overfeed the fish. Make sure you cycle your aquarium properly. Use a silicate free source of water such as reverse osmosis water.
Brown algae in a saltwater tank
Check for silicates in your saltwater mix. Look through the list of ingredients to see if any silica based compound is in the list. Try using reverse osmosis water rather than tap water for your saltwater mix. Make sure you clean the brown algae off the corals daily. Use a phosphate/silicate-absorbing material in the filter.
Fungus – the ever present danger – to fish and eggs
There are many species of aquatic fungus but by far the most common two are saprolegnia and achlya.
Symptoms of fungal attack
Fungus occurs as white, grey and sometimes brown fluffy growths on the skin or fins of fish or on developing eggs from a spawning.
Saltwater fish actually suffer less, than freshwater fish, from fungus because of the salt in a marine environment. However, brackish water fish, even mollies, when kept in insufficiently salty water are the most prone to fungal attacks.
Fungus often starts as a small tuft, and usually spreads when not treated and can kill a fish if the fungus penetrates the internals of the fish. Fish eggs if not treated or infected eggs are not removed can cause all nearby eggs to be infected and killed.
What causes fungus to develop
Fungus and fungal spores thrive in damp environments with decaying organic matter and an aquarium is full of water so is ripe for fungal outbreaks. Fungus sprouts where there is decaying organic matter, dead fish, or unfertilised or dead fish eggs. When fungus grows it releases millions of spores into the water which will quickly infect any fish that has a break in its protective mucous which may occur after rough handling or an attack from another fish or bumping into aquarium rocks.
Parasitic diseases such as ich, body ulcers and infections will damage the protective mucous and allow entry of fungal spores, compounding the fish’s problems.
When fish are kept in poor quality water conditions with water that is full of bacteria, nitrites, ammonia and excessive fish waste then they are much more likely to get infected by fungus.
Fungus treatment for fish eggs
With fish eggs any unfertilised eggs or dead eggs will quickly get infected with fungus. If that egg is not quickly removed then the fungus will spread and infect otherwise healthy eggs. All adjacent eggs may be killed.
Prevention of egg infection by fungus is achieved by adding methylene blue to the water immediately after the eggs have been spawned. Be careful not to overdose because eggs may suffer developmental problems. Also remove any off-white eggs with a pipette before they become heavily infected.
Cichlids actually do a good job in removing dead and unfertilised eggs and keeping the eggs free from dirt as part of their parental care.
Fungus treatment for fish
Treat as soon as possible. use an aquatic antifungal remedy from your local aquarium shop. Place any heavily infected fish in a quarantine tank and treat the fish there. In the main aquarium a dose of salt added to the water should heal slightly infected fish and help to kill of most spores present.
Prevention is better than cure and this is a mostly preventable illness. Remedy the environment of the aquarium that led to the original outbreak. If it was an accident such as a dead fish then a salt dose to the aquarium should be sufficient.
However, if the cause was rotten food then you must keep up good feeding practices of not feeding more than the fish will eat. Observe all the food you place into the aquarium and remove any uneaten food with a siphon. When your aquarium has a nitrite or an ammonia spike then fish will go off their food. If you feed at this time then you will surely cause a disaster.
Make sure your filter is fully cycled. Make sure that the water you add to the aquarium has the chlorine removed before adding. Also, siphon through and disturb the gravel to remove any build up of fish waste. And make sure your filter has not become clogged. If the filter is clogged then squeeze out the excess dirt from the sponge into a bucket of aquarium water.
And finally, keep up good maintenance practices. Then you should never have a problem with fungus again.
Anchor worms are so called because it has an organ that looks like a ship’s anchor which it uses to attach itself to the body of a fish. Scientists call anchor worms Lernea. This is a parasite that is visible to the naked eye. What you will see is long straight worm like lines attached all over a fish’s body. The end of the “lines” forks into two parts. These are actually the egg pouches of a female anchor worm. There are male and female anchor worms but the male anchor worms die after mating so you will mostly see the females.
The harm caused by anchor worms
Anchor worms don’t just attach themselves to the body of the fish but actually embed the “anchor” deep into the flesh, muscles and even as deep as internal organs. Where the anchor worm penetrates the skin a swollen red ulcer will develop. This sore usually leads to secondary fungal or bacterial infections. The anchor worm drains the fish by feeding off its blood.
Life cycle of anchor worms
The female anchor worm will release her eggs into the water when they are about to hatch into free swimming larvae. These larvae will swim about for up to a week looking for a fish to attach itself to. If they don’t attach themselves in this time they will die off.
The larvae will go through a juvenile stage and an adult stage. At the adult stage they will mate, with the males dying off, leaving behind the females with her eggs. The females stay attached waiting for her eggs to mature.
Treatment of anchor worms
To treat anchor worms successfully, you need a two pronged approach. One part involves taking each infected fish out of the aquarium, one by one to remove the anchor worms. Use tweezers and grab the anchor worm near to the attachment point. Grab tightly and pull it out quickly before the worm has a chance to react. Dab the sore on the fish with an aquatic antiseptic. The second part of the treatment involves adding a chemical treatment to the water to kill off any free swimming larvae in the water. Use an organophosphorous insecticide such as metriphonate.
After one week repeat the treatment. Remove any new anchor worms that have attached and treat the water again in case there are any new free swimming larvae.
Luckily anchor worms are quite rare and when it does occur they are easily spotted. Infection usually comes from newly introduced fish or from birds that bring it to ponds.
Keeping aquarium plants healthy is vital. However, most aquarists put the welfare of their fish first and are not willing to promote the health of their plants, if it may affect their fish. I will explain how you can do both. And, the two are not mutually exclusive. Healthy plants can promote health in your fish.
If your planted aquarium is not regularly maintained, it can quickly become a jungle. Quick growing plants will out grow smaller and slower growing species. The larger plants will hog the light resulting in the smaller plants not getting enough light. Fish waste and plant sheddings will accumulate, polluting the water. Fortunately, maintenance is not time-consuming if carried out every week. If you do half an hour a week maintenance then your aquarium plants will be kept in tip top condition. To the right is what an otherwise healthy planted aquarium looks like when trimming and maintenance has been neglected. With a bit of trimming and relocating of plants this could look like a cracking aquarium and you could actually get to see the fish.
But it is not just the welfare of the plants you need to also take care of the lighting, filtration, water quality and the fish. All these factors also affect the plants.
Every aquarium is different so I will give a general guideline which you will have to adapt to your specific set of plants and aquarium.
Relocating aquarium plants
Plants will naturally grow and spread with new offshoots. Some will grow so much that they crowd out other smaller or slow growing species. Also, you might do a spring clean or fancy a change of scenery. All this means that you will have to relocate some plants.
You can’t just uproot a plant and plant it somewhere else. You have to consider its root system which might be quite extensive if the plant is well established.
When removing a plant take out as much of the root system as possible, avoid ripping roots. Try to take out all the surrounding substrate with the roots intact if you can. If this is not possible, then use your fingers to gently tease out the roots without disturbing the gravel too much.
Once you have extracted the plant then knock off any attached gravel or dirt. Then, trim any long roots to just a few centimetres. Long stringy roots are not easily replanted and are easily damaged. Once replanted the plant will grow new roots and become re-established much quicker.
When you replant, create a hollow in the gravel. Put the roots into the hollow. Put a fertiliser tablet underneath or on the roots, then pack the gravel around the roots. The fertiliser tablet will speed up the plant’s recovery.
It is rare for plants to actually suffer from disease such as bacterial infections or viruses. Except for crypts there are no common aquarium plant diseases. When your plants start displaying symptoms of ill-health these are almost certainly caused by environmental harm or nutritional deficiencies.
If you spot any symptoms early then the remedy is usually quite simple with the plant making a quick and complete recovery.
Cryptocoryne rot is a condition that only affects crypt plants. It looks like small holes in the leaves or the leaf edges. It is not certain what the cause is but it can be set off by a change of environment such as high nitrates, lack of water changes and lack of lighting. Crypts usually recover quickly once you have found the cause and fixed the problem. However, if left the plant can completely break down and die.
Aquarium plant poisoning
This is usually caused by adding medications to cure fish ailments. But could also come from recently added ornaments or rocks. After medicating your fish, use a chemical filter with activated carbon, for example, to remove all chemical residues to reduce any harm from the medication. Saying this, most medications are harmless or only slightly harmful.
But this is not the case with algicides which can harm plants. If at all possible it is better to cure your algae problem without using chemicals.
Another possible harmful substance is hydrogen sulphide that may form in the gravel or sand where anaerobic conditions allow food to rot to give off this poisonous gas. One last possible source of poisoning is from over use of fertiliser, which is beneficial in normal doses but can become a poison with over use.
Snail damage to aquarium plants
Snails in small numbers are unsightly and a nuisance. But, in large numbers they can take a toll on your plants by chewing away little by little every day. They are usually introduced to your aquarium as eggs attached to the under side of plant leaves. The eggs look like blobs of jelly and are difficult to see especially when the plant is in water.
Once snails get established in the aquarium it is impossible to completely eradicate them by hand. You could try adding snail eating fish or even assassin snails that chase and eat snails. This will help keep the numbers down.
You have to eradicate snails from plants before placing the plants in the aquarium by dipping the plants in an anti snail solution that will kill off the snails. Then wash off any chemicals before placing the plant in the aquarium. It is not recommended to add chemicals to the aquarium because the chemicals can harm the plants and fish.
Fish harming the plants
Unless you keep plant eating fish then it is unlikely that your fish are causing much damage to your plants. The only exception is with cichlids and other large fish that can tug at the plants and uproot them. What may look like fish bites out of your plants is usually some other cause.
Algae occurs naturally in all aquariums that have some light and some nutrients. If you keep plants you will also get algae. Small amounts of algae growing slowly on rocks, driftwood and large plant leaves are of little consequence to your plants or your aquarium. Indeed, your fish may enjoy a nibble from time to time. And, the algae helps in the removal of fish waste products.
However, when conditions in the aquarium, such as excess light, wrong type of light or excess nutrients occur then an algae bloom is a real danger. The pea soup effect which is unsightly, will be disastrous for your plants, preventing light getting to your plants. An algae bloom can also release dangerous gases into the water.
Green water, caused by algae bloom, cannot be filtered out, and even if you used a filter with a very fine media, that filter would quickly become choked. Also if you try to remove the algae by changing the water, you will make matters worse. New tap water has dissolved nutrients that will feed the algae.
Treatment of algae in the aquarium
Reduce the lighting quantity and duration of the lighting and make sure no sunlight reaches the aquarium. Remove excess waste matter on a daily basis using a siphon. When feeding make sure that your fish eat all the food fed to them. Any uneaten food will rot and create waste products that feed algae.
The problem of blue-green algea
This is like a slime that covers just about every surface in the aquarium. Although typically bluey-green can also be greenish-brown or even black. Algae eating fish will not eat it. You can siphon off most of it using a siphon pump but it will re-occur. The solution is to reduce any fertiliser and any nutrients getting into your aquarium from fish waste and uneaten foods.
Blanket weed problems
This fibrous, hair like, algae grows on surfaces. it will cover plants and decor and is hard to remove. It is caused by an excess of light, especially sunlight, and excess of organic matter in the water. Chemicals are largely uneffective against it. The only solution is to remove as much of the algae as possible by hand. Then thoroughly clean the gravel with a siphon to remove excess organic waste.
For algae – prevention is better than cure
Although a small algae bloom is almost inevitable in a new aquarium, the problem is largely avoidable. Here is a list of preventative measures that if you follow will prevent algae ever getting a foothold.
Have a few algae eating fish. Small species such as otocinclus is ideal.
Avoid an excess of fertiliser. Using fertiliser tablets on a plants roots is better than pouring liquid fertiliser into the water. Ferilisers with phosphates are the worst culprit, so use a fertiliser without phosphates.
Avoid direct sunlight. Even well maintained aquariums can attract algae when placed in direct sunlight.
Lighting should be on for less than 12 hours per day.
Make sure you use the correct type of bulb with the correct wattage for your aquarium. In other words, buy a bulb that gives off the correct wavelength of light and is of the right brightness for your size of aquarium.
Clean the gravel properly and regularly by sifting through the gravel with a siphon removing accumulated fish waste. Do not remove the gravel to wash under the tap.
Do regular water changes to dilute the excess of nitrates and phosphates that accumulate in the aquarium.
Finally, alleopathy can stop certain plants growing together
Certain plants release chemicals that are harmful to certain other plants. So that when one type of plant is in an aquarium, it is impossible to grow another incompatible species of plant in the same aquarium. Even, when the aquarium conditions are perfect for the incompatible plant it just will not grow until you remove the first plant. Not much is known about this process, so there isn’t a guide to tell you which plants are incompatible with other plants.
Your aquarium is very similar to a carefully-tended garden in many ways, especially when it comes to unwanted pests that can accumulate, often rapidly, and begin causing damage to your delicate aquatic ecosystem. There are numerous types of aquarium pests and fish parasites that, if left unchecked, can seriously affect the health of your fish and even kill them.
Some of the most common pests that you will find in a typical tropical aquarium are as follows:
Algae – This is by far the most common pest, and it comes in many flavours: brown algae, hair algae, bubble algae, slime algae and more. Most of these are easily controlled by addressing your tank’s water quality and level of light exposure. Though not harmful to your fish, it is unsightly.
Snails – These small creatures can suddenly appear in your tank, where they will begin to eat your live plants and reproduce rapidly. If left unchecked, they will push your tank’s biological load far past its limit. They also eat fish eggs.
Hydra – Tiny freshwater polyps that like to feed on fish fry, Hydra can be very difficult to eliminate from your tank once an infestation begins. They can also irritate larger fish and are generally unwanted even if you do not have fry present.
Planaria – These creatures occur as a result of overfeeding or bad water management. Although not harmful to fish, though they may irritate the fish, they are unsightly and are a sign that the aquarium is not well cared for.
Floating Plants – If left to grow unchecked, floating plants can become a nuisance and need to be trimmed down to size.
How aquarium pests get introduced to your aquarium
The one major difference between your fish tank and a garden is the fact that your aquarium, at least in theory, is a closed ecosystem. You may be asking yourself how aquarium pests occur in such an environment: Most commonly, they are introduced as eggs, larvae or pupae on rocks, driftwood, and other aquarium decorations that have not been thoroughly cleaned.
The most effective way to prevent most of these pests from invading your aquarium is to carefully clean anything that you introduce to your aquarium. Snail eggs can ride in on live plants, or even with newly bought fish in some circumstances, which makes absolute prevention impossible. Pest control is occasionally still necessary, however. Another sure way is to absolutely avoid adding new objects, plants and fish to the aquarium.
What to do about aquarium pests in your tank
By far the most common pest is unwanted algae, which is relatively simple to control. New aquariums are particularly vulnerable to brown algae, which will usually go away on its own after the aquarium becomes properly established. Regular water changes and a strictly controlled lighting set up will discourage algae from growing, as will the introduction of plants to your tank.
Algae grows as a response to certain wavelengths of light. If your lights are old the wavelength changes, which may encouraging algae growth. If you continue to have problems despite using the correct lighting, it is a sign that your water is saturated with nutrients. A protein skimmer can help remove the organic waste that algae feeds on. A reverse osmosis water filtration system can remove nutrients before they enter the aquarium. Another option for immediate control is blocking out all light entering your aquarium for a few days.
Snails can be controlled by a variety of means. You can crush the shells yourself and let the fish eat their remains. Or add a snail-eating loach to your tank. You can also buy assassin snails which will hunt down and eat your snails reducing the number of snails. Another way to reduce the snail population is by adding copper to your water, which is a toxic substance for most aquatic invertebrates. Small copper coins can work, although they must be cleaned before introduction to the tank.
When it comes to hydra, the problem can get a bit more complicated. Chemical solutions exist, but can be harmful for live plants, fish and the beneficial bacteria in your filter. A better way to control these creatures is through the introduction of hydra-eating fish like three-spot blue gouramies. If that is not an option, you will have to cook them.
Hydra will die at a temperature greater than 40°C, which is less than what would kill your beneficial bacteria, so if you temporarily remove your fish and raise the heat to this temperature for a few hours, your tank will be free of these aquarium pests. You can then turn the heat back down, vacuum your gravel and perform a 50% water change to clear the tank. Once the water temperature is back to normal, you can re-introduce your fish safely.
Planaria are often much more difficult to contain. They will generally have to be physically removed or starved through decreased feeding. These worms can regenerate when physically damaged, making them particularly problematic in large numbers. Many aquarists find that chemical solutions are the only effective solution when dealing with a planaria infestation. However, some gouramis, guppies betta, mollies and kribensis sometimes eat them.
Controlling your plants’ growth
When it comes to controlling the growth of plants in your tank, you will need to take a more careful approach since these are organisms you want in your tank, but at levels and sizes that your aquarium can support. Plants can be particularly troublesome since an improperly trimmed stem will simply grow back, often bigger than before.
The key to proper plant control is to use specialized aquascaping tools to trim your plants. Aquascaping scissors allow you to use the correct technique when trimming your plants: cut stems should be sliced at a diagonal angle that prevents the plant from simply regenerating the stem. This is very difficult to do with regular scissors, but very easy with a pair designed specifically for aquascaping.
Fish parasites and diseases
Many of the more common aquarium pests take the form of fish parasites that infect your fish and make them sick. These can seriously affect the health of your fish and often need to be addressed using a separate quarantine tank in order to separate the infected fish from the rest of your tank. Common fish parasites include:
Ick(ich) – This is a very common problem for fish that are stressed as a result of rapid changes in water quality or temperature. Ick infections make your fish look like it has tiny white grains of sand covering its body. Commercial cures are available in tablet form or liquid form. However, they don’t always work because some strains of ick have become immune. Raising the temperature for a week and dosing the tank with salt usually works.
Gill Flukes – These tiny flatworms infect the gills of your fish, and can be identified with symptoms similar to ick but with erratic movement and eye spots on the scales. Flukes cannot be seen with the naked eye. Often encouraged by poor water quality or overcrowded tanks, gill flukes must be treated immediately with anti-parasitic aquarium tablets.
Water Lice – If your fish seem to have pale, tiny eight-legged crabs on their bodies, you are looking at fish lice. These aquarium pests need to be physically removed from the fish and the wound treated with an antiseptic such as iodine. Another common solution is bathing freshwater fish in a salt bath of 35 ppt seawater for 5 minutes every day until the parasite falls off.
Gill Mites – These microscopic creatures can be identified if your fish is gasping at the water’s surface and has partially opened gill covers showing inflammation or infection. They must be treated with anti-parasitic treatments in tablet form, with water changes in between each treatment.
Hopefully, you will never have to deal with any of these aquarium pests or fish parasites. But, you should always be prepared to put a plan into action as soon as any of these pests are first spotted, before they cause problems to your plants or fish.
Once a problem has been cured, that is not the end of the matter. It is vital that you correct the conditions that caused the problem in the first place. Overfeeding, poor water quality, lighting problems, overcrowding are conditions that must be recognised and corrected so that the problems do not re-occur.