Krish
RF STAFF
Thought I'd put together a little write up on problem algae's out there seeing the topic always pops up. These are just my personal thoughts and views on it and may not be 100% accurate. Please feel free to add to, comment or suggest anything related to the topic. It's also open for complete discussion. 
"Algae", being a simple photosynthetic organism, has been around for centuries in which they come in many different forms, shapes and sizes. For those who allow them to get out of control to where they are un-manageable in their aquariums, have given them the bad "rep" as being referred to as a nuisance. Not all "algae" are bad though as they are needed to provide oxygen and food for marine life, but it is when we allow certain types to take over our tanks, that they do become a problem. This article will touch on the most common types of nuisance algae's found in this hobby and ways of preventing and controlling them.
Chiton(curb) consuming algae growing on an overflow box
So before we get into ways of treating and controlling algae in our aquariums, let's first identify the common types of nuicance algae's you may encounter in this hobby.
Diatoms- One of the first types of nuisance algae's to make it's way into our aquariums are diatoms...Otherwise known as "Brown Algae" or "Golden Brown Algae". It is easily distinguished by its appearance being brownish in color (as its name suggests) and is usually seen on the top layer of your substrate (almost like a film), over your tank walls and even all over your rocks. In essense, they will pretty much cover any surface.
Photo uploaded from and property of Scubs' Adventure
More in depth reading on diatoms can be found here http://www.reeffrontiers.com/forums/f14/diatoms-60176/
Green Hair Algae- This algae is usually easily distinguished by it's green color (due to containing chlorophyl) and also by it's appearance. Basically as it's name suggests, it looks like "green hair" or a "green bush" growing all over your rocks. This type of algae, unlike diatoms, doesn't feel slimey to the touch and can't be wiped off of surfaces as easily as diatoms can. Hair algae usually gets a good foot hold on whatever it is attached to by anchoring itself to the surface. So manual removal will actually require you to physically pull it off of the rocks they are anchored to or to scrub them off aggressively with a scrub brush. Be careful though as you can release spores back into the water column.
Photo of Nikki's tank while going through a hair algae outbreak
Cynobacteria/Red slime Algae - Cynobacteria/red slime algae is basically not an algae nor a bacteria, but rather a combination of both. As seen mostly in our aquariums, this type of "algae" will usually be red in color and can be found on pretty much any surface (like diatoms) in the form of a mat. I has been found to grow on rocks, substrate and even tank walls where flow in minimal. Sometimes you will even notice small bubbles forming in it.
Red cyno beginning to form on liverock
Cyno taking over rocks and substrate
Polishing cartridge seen after vacuuming cyno next to a new catridge
Coralline Algae - It's hard to believe with all of the, "How Do I Get Coralline To Grow?" threads and products on the market like "Purple-Up" to promote coralline growth, but yes, coralline algae can actually become a nuicance if you let it get out of hand. Coralline unlike other "algae's" use trace elements found in water (some of which corals use) for their growth so having a lot of coralline algae growing in your tank, may require you to bump up your calcium, alk etc doses to keep up with the demand and keep water parameters balanced. In many cases, you will see every surface covered in coralline. Some people love the look and aren't happy unless their tank is plastered in it, but then there are some, who want to contain it and only have it growing on their rocks. These are the people who will consider it a nuisance if it started growing everywhere and in places they didn't want it to grow. Coralline does add a bit of color and beauty to your tank, but too much of anything sometimes can have negative effects. This type of algae however grows best where water quality is top notch unlike other algaes that flourish in nutrient rich water. For more info on coralline algae, take a peek at this article on coralline algae Coralline Algae Article
Photo taken from Coralline article of Charlie's tank giving you an example of coralline covering every surface.
Dinoflagellates - Most commonly found in our aquariums that actually drive some hobbyist into wanting to throw in the towel is the photosynthetic "dino's." They best way to describe it's appearance is that it looks like a mat of snott covering basically anything in your tank. It can also be toxic and is usually seen in our aquariums either in a brown or green color although they come in other colors and forms as well. You can usually distinguish them from other similar looking algae's by them containing tons of oxygen bubbles in them.
Photo uploaded and property of Dinoflagellates - 3reef Forums
Bubble Algae - Ohhh...I hate these fellas!! Bubble algae come in many different forms, species, shapes, colors and sizes. Just as the name suggests, most of what we see in our aquariums looks just like the name suggests...Bubbles (most of which I've seen are usually green). The problem with bubble algae is you have to be careful when trying to remove them. Usually when they are in their "mature stage", if you try to manually remove them and accidentally pop the "bubble", it will relelase spores into your tank causes more of them to form. Out of all of the different types of bubble algae's out there, the species "Valonia" has to be probably the most aggressive and most hated ones.
In order to understand how to prevent and control algae, you must first understand what causes it to grow. Like every other photosynthetic plant, a few things are needed for growth to take place...Lighting and nutrients. The type of nutrients found in our tanks that algae will consume for it's growth will include predominantly nitrates and phosphates. Silicates in water will also fuel algae's like diatoms to grow as well. So how do they get in there? Here is a list of ways nitrates and phosphates are introduced or accumilated into the aquarium:
There are a few ways algae is introduced in our tanks. Some of the most common ways are:
and the list goes on...
Depending on which approach you want to take, there are many ways to treat and control algae growth. As menitoned earlier, algae isn't always a bad thing as all marine life relies on it in one way or the other whether it be a food source, to provide oxygen or whatever. When it gets to the point where it is smothering your corals blocking them from getting light etc, then it can become a problem. Plus who wants to look at a tank full of algae? Not very many people so here are a few ways to treat and/or control algae.
Manual Removal - One way of limiting algae in your tank is to manually remove it. As algae grows, it binds up the excess nutirents in the water (nitrates and phosphates) and by manually removing it, this will allow you to export these same excess nutrients out of your system. Some people will harvest an algae and keep it in a refugium where this process takes place. They use a hardy algae to consume up whatever excess nutrients are present in the water column and by doing this in a refugium, the algae can be kept out of the main display and out of sight. Each algae has it's very own specific technique that should be used to manually remove algae so be sure to be fully informed how to go about the manual removal of any algae before just jumping in there and grabbing at it.
Use of CUC's and Fish - This one can be a bit tricky. It is debated that although fish or a clean up crew (CUC) will eat some of the algae or even waste found in the tank, that these same things "poop" as well adding waste right back into the water. However, going on the "exporting nutrients" out of your system idea, fish and inverts can help with this. A tang can do major algae control damage in a short amount of time. These fish graze all day so although they may continue to add to the waste production, you may not really even notice it because as the nitrates and phosphates are made available to the algae and it begins to grow, the Tang ( in this case) will consume it quickly leaving nothing behind but a tank looking algae free.
RO/DI Water- Unless your water was tested and found suitable for aquarium use, ro/di water should be used almost in all cases. Most tap water contains all of the nasty stuff we are trying to keep out of our tanks from nitrates to phosphates to silicates etc. By using ro/di water, you aren't adding "fuel" to feed the algae so the less "fuel" provided to feed the algae, the less of it will grow.
Chemicals - Some people will use chemicals to aid in erradicating algae from a system, but you have to be very careful here. A lot of chemicals used are copper based which can be harful to all of your tank inhabitants including your corals, inverts and fish so this option is usually avoided if at all possible.
Lighting - Algae tends to prefer lighting in lower kelvin range (about 6500K or there about). As bulbs age, they start to lose their "color" a bit and the specturm beings to change to a "color" that is more suited for algae/plant growth. This is why it is suggested to change your bulbs regularily even if they are still firing up each day and the color looks the same to the naked eye. It all depends on what bulb you are using (metal halide, compact flourescent, VHO's, T-5's etc) that will determine how often they should be changed.
Tank Maintenance/Husbandry- Tank maintenance is very important. Sponges/filter floss/filter socks etc. trap waste and if they aren't changed or replaced regularily, all that trapped waste will begin to rott which in turn shoots up nitrate and phosphate levels. If you have inadequet flow in your tank, detritus piles will usually form that need siphoning out. Same thing goes for the rocks. Inadequet flow will leave an accumilation of detritus on your rocks so all of that will have to be blown off and siphoned up. Any left behind deagrades water quality. In some cases, weekly water changes of about 10-15% should be done. It is during this time people will usually vacuum out the waste from their tank and even vacuum their sandbed removing any waste that may be trapped in there. You have to take caution here though as different sandbeds require different maintenance so you have to fully understand how to care for your particular sandbed. In addition to all of the above, you will need to remember to change out your carbon and phosphate media on time (if you are running any) as well as to remember to keep your skimmer neck cleaned. And last, but not least, if you are running a refugium with an "algae" in there, you will have to remember to periodically trim it back some to export all of that bound up nutrients it took in that it uses for it's growth out of your system.
Finding the "Food Source" or "Fuel"/ Nutrient supression - A lot of the time, you will hear people say they have an algae outbreak and they ask a number of questions like..What do I do? What fish will eat it? Which critters will make quick work of it? Or even what chemical can I add in my tank to get rid of it? The answer to many of these questions will only temporarily mask the problem. In order to really erradicate a nuisance algae, you will need to find what in your system is fueling it to grow. It can be anything from over feeding, overstocking, neglecting tank maintenance/husbandry, using tap water etc so you will have really dig in and narrow down what is fueling your algae to grow and address it. It can be something as simple as adding to much food to your tank each day that goes un-eaten which sits and rotts. Also keep in mind that a new tank will have to cycle and find its balance so during this time, nuisance algaes will grow and sometimes you have to just stick it out. Eventually as your tank matures, the algae will begin to disappear as it's pimary food source won't be available.
So in conclusion, algae is not necesarily a bad thing, but as mentioned, too much of anything can some times become a problem. Also, there are just some algae's out there that cause more harm than good to a tank (prime example algae covering and smothering a rock or corals from recieving light). Algae's presence in a tank, in most cases, is usually a clear indication that something may be "off" and that there are excess nutrients in the tank feeding/fueling the algae to grow so you may want to look into the source if the sight of algae bothers you. With that said, algae does provide it's abundance of benefits to the aquarium and marine life (as was touched on previously in the article) so don't think of it as only being a bad thing. Without algae in some form, marine life would cease to exist.
Problem Algae's: Causes/Treatment/Control
"Algae", being a simple photosynthetic organism, has been around for centuries in which they come in many different forms, shapes and sizes. For those who allow them to get out of control to where they are un-manageable in their aquariums, have given them the bad "rep" as being referred to as a nuisance. Not all "algae" are bad though as they are needed to provide oxygen and food for marine life, but it is when we allow certain types to take over our tanks, that they do become a problem. This article will touch on the most common types of nuisance algae's found in this hobby and ways of preventing and controlling them.
Chiton(curb) consuming algae growing on an overflow box
Types of Nuisance Algae
So before we get into ways of treating and controlling algae in our aquariums, let's first identify the common types of nuicance algae's you may encounter in this hobby.
Diatoms- One of the first types of nuisance algae's to make it's way into our aquariums are diatoms...Otherwise known as "Brown Algae" or "Golden Brown Algae". It is easily distinguished by its appearance being brownish in color (as its name suggests) and is usually seen on the top layer of your substrate (almost like a film), over your tank walls and even all over your rocks. In essense, they will pretty much cover any surface.
Photo uploaded from and property of Scubs' Adventure
More in depth reading on diatoms can be found here http://www.reeffrontiers.com/forums/f14/diatoms-60176/
Green Hair Algae- This algae is usually easily distinguished by it's green color (due to containing chlorophyl) and also by it's appearance. Basically as it's name suggests, it looks like "green hair" or a "green bush" growing all over your rocks. This type of algae, unlike diatoms, doesn't feel slimey to the touch and can't be wiped off of surfaces as easily as diatoms can. Hair algae usually gets a good foot hold on whatever it is attached to by anchoring itself to the surface. So manual removal will actually require you to physically pull it off of the rocks they are anchored to or to scrub them off aggressively with a scrub brush. Be careful though as you can release spores back into the water column.
Photo of Nikki's tank while going through a hair algae outbreak
Cynobacteria/Red slime Algae - Cynobacteria/red slime algae is basically not an algae nor a bacteria, but rather a combination of both. As seen mostly in our aquariums, this type of "algae" will usually be red in color and can be found on pretty much any surface (like diatoms) in the form of a mat. I has been found to grow on rocks, substrate and even tank walls where flow in minimal. Sometimes you will even notice small bubbles forming in it.
Red cyno beginning to form on liverock
Cyno taking over rocks and substrate
Polishing cartridge seen after vacuuming cyno next to a new catridge
Coralline Algae - It's hard to believe with all of the, "How Do I Get Coralline To Grow?" threads and products on the market like "Purple-Up" to promote coralline growth, but yes, coralline algae can actually become a nuicance if you let it get out of hand. Coralline unlike other "algae's" use trace elements found in water (some of which corals use) for their growth so having a lot of coralline algae growing in your tank, may require you to bump up your calcium, alk etc doses to keep up with the demand and keep water parameters balanced. In many cases, you will see every surface covered in coralline. Some people love the look and aren't happy unless their tank is plastered in it, but then there are some, who want to contain it and only have it growing on their rocks. These are the people who will consider it a nuisance if it started growing everywhere and in places they didn't want it to grow. Coralline does add a bit of color and beauty to your tank, but too much of anything sometimes can have negative effects. This type of algae however grows best where water quality is top notch unlike other algaes that flourish in nutrient rich water. For more info on coralline algae, take a peek at this article on coralline algae Coralline Algae Article
Photo taken from Coralline article of Charlie's tank giving you an example of coralline covering every surface.
Dinoflagellates - Most commonly found in our aquariums that actually drive some hobbyist into wanting to throw in the towel is the photosynthetic "dino's." They best way to describe it's appearance is that it looks like a mat of snott covering basically anything in your tank. It can also be toxic and is usually seen in our aquariums either in a brown or green color although they come in other colors and forms as well. You can usually distinguish them from other similar looking algae's by them containing tons of oxygen bubbles in them.
Photo uploaded and property of Dinoflagellates - 3reef Forums
Bubble Algae - Ohhh...I hate these fellas!! Bubble algae come in many different forms, species, shapes, colors and sizes. Just as the name suggests, most of what we see in our aquariums looks just like the name suggests...Bubbles (most of which I've seen are usually green). The problem with bubble algae is you have to be careful when trying to remove them. Usually when they are in their "mature stage", if you try to manually remove them and accidentally pop the "bubble", it will relelase spores into your tank causes more of them to form. Out of all of the different types of bubble algae's out there, the species "Valonia" has to be probably the most aggressive and most hated ones.
Understanding What Causes Algae To Grow
In order to understand how to prevent and control algae, you must first understand what causes it to grow. Like every other photosynthetic plant, a few things are needed for growth to take place...Lighting and nutrients. The type of nutrients found in our tanks that algae will consume for it's growth will include predominantly nitrates and phosphates. Silicates in water will also fuel algae's like diatoms to grow as well. So how do they get in there? Here is a list of ways nitrates and phosphates are introduced or accumilated into the aquarium:
- Un-eaten fish food left in the tank to rott
- Waste in the form of fish poop etc being left in the tank
- Using tap water not found suitable for aquarium use
- Neglecting tank maintenance (ie water changes, vacuuming substrate, changing out filter pads, floss and media on schedule)
- Over stocking a tank to where filtration can't keep up with waste production
- Newly set up tanks that have not matured and found their "balance"
How does algae get in our tanks?
There are a few ways algae is introduced in our tanks. Some of the most common ways are:
- Through the introduction of liverock that has spores already in it
- Adding a colony of corals like zoanthids (as an example) that may have some bubble algae entangled up in it that you may miss
- The introduction of fish that may already have algae in their digestive system that they then poop some of it out in your tank
and the list goes on...
How to Treat and Control Nuicance Algae's
Depending on which approach you want to take, there are many ways to treat and control algae growth. As menitoned earlier, algae isn't always a bad thing as all marine life relies on it in one way or the other whether it be a food source, to provide oxygen or whatever. When it gets to the point where it is smothering your corals blocking them from getting light etc, then it can become a problem. Plus who wants to look at a tank full of algae? Not very many people so here are a few ways to treat and/or control algae.
Manual Removal - One way of limiting algae in your tank is to manually remove it. As algae grows, it binds up the excess nutirents in the water (nitrates and phosphates) and by manually removing it, this will allow you to export these same excess nutrients out of your system. Some people will harvest an algae and keep it in a refugium where this process takes place. They use a hardy algae to consume up whatever excess nutrients are present in the water column and by doing this in a refugium, the algae can be kept out of the main display and out of sight. Each algae has it's very own specific technique that should be used to manually remove algae so be sure to be fully informed how to go about the manual removal of any algae before just jumping in there and grabbing at it.
Use of CUC's and Fish - This one can be a bit tricky. It is debated that although fish or a clean up crew (CUC) will eat some of the algae or even waste found in the tank, that these same things "poop" as well adding waste right back into the water. However, going on the "exporting nutrients" out of your system idea, fish and inverts can help with this. A tang can do major algae control damage in a short amount of time. These fish graze all day so although they may continue to add to the waste production, you may not really even notice it because as the nitrates and phosphates are made available to the algae and it begins to grow, the Tang ( in this case) will consume it quickly leaving nothing behind but a tank looking algae free.
RO/DI Water- Unless your water was tested and found suitable for aquarium use, ro/di water should be used almost in all cases. Most tap water contains all of the nasty stuff we are trying to keep out of our tanks from nitrates to phosphates to silicates etc. By using ro/di water, you aren't adding "fuel" to feed the algae so the less "fuel" provided to feed the algae, the less of it will grow.
Chemicals - Some people will use chemicals to aid in erradicating algae from a system, but you have to be very careful here. A lot of chemicals used are copper based which can be harful to all of your tank inhabitants including your corals, inverts and fish so this option is usually avoided if at all possible.
Lighting - Algae tends to prefer lighting in lower kelvin range (about 6500K or there about). As bulbs age, they start to lose their "color" a bit and the specturm beings to change to a "color" that is more suited for algae/plant growth. This is why it is suggested to change your bulbs regularily even if they are still firing up each day and the color looks the same to the naked eye. It all depends on what bulb you are using (metal halide, compact flourescent, VHO's, T-5's etc) that will determine how often they should be changed.
Tank Maintenance/Husbandry- Tank maintenance is very important. Sponges/filter floss/filter socks etc. trap waste and if they aren't changed or replaced regularily, all that trapped waste will begin to rott which in turn shoots up nitrate and phosphate levels. If you have inadequet flow in your tank, detritus piles will usually form that need siphoning out. Same thing goes for the rocks. Inadequet flow will leave an accumilation of detritus on your rocks so all of that will have to be blown off and siphoned up. Any left behind deagrades water quality. In some cases, weekly water changes of about 10-15% should be done. It is during this time people will usually vacuum out the waste from their tank and even vacuum their sandbed removing any waste that may be trapped in there. You have to take caution here though as different sandbeds require different maintenance so you have to fully understand how to care for your particular sandbed. In addition to all of the above, you will need to remember to change out your carbon and phosphate media on time (if you are running any) as well as to remember to keep your skimmer neck cleaned. And last, but not least, if you are running a refugium with an "algae" in there, you will have to remember to periodically trim it back some to export all of that bound up nutrients it took in that it uses for it's growth out of your system.
Finding the "Food Source" or "Fuel"/ Nutrient supression - A lot of the time, you will hear people say they have an algae outbreak and they ask a number of questions like..What do I do? What fish will eat it? Which critters will make quick work of it? Or even what chemical can I add in my tank to get rid of it? The answer to many of these questions will only temporarily mask the problem. In order to really erradicate a nuisance algae, you will need to find what in your system is fueling it to grow. It can be anything from over feeding, overstocking, neglecting tank maintenance/husbandry, using tap water etc so you will have really dig in and narrow down what is fueling your algae to grow and address it. It can be something as simple as adding to much food to your tank each day that goes un-eaten which sits and rotts. Also keep in mind that a new tank will have to cycle and find its balance so during this time, nuisance algaes will grow and sometimes you have to just stick it out. Eventually as your tank matures, the algae will begin to disappear as it's pimary food source won't be available.
Conclusion
So in conclusion, algae is not necesarily a bad thing, but as mentioned, too much of anything can some times become a problem. Also, there are just some algae's out there that cause more harm than good to a tank (prime example algae covering and smothering a rock or corals from recieving light). Algae's presence in a tank, in most cases, is usually a clear indication that something may be "off" and that there are excess nutrients in the tank feeding/fueling the algae to grow so you may want to look into the source if the sight of algae bothers you. With that said, algae does provide it's abundance of benefits to the aquarium and marine life (as was touched on previously in the article) so don't think of it as only being a bad thing. Without algae in some form, marine life would cease to exist.
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