A common problem in aquarist’s reef aquariums is the presence of brownish algae coating everything from the sand to the live rock to the glass. It can look unpleasant and outright disgusting if it is allowed to thrive but did you know that not all brown alga is created equal? Specifically diatom algae vs dinoflagellates.
The easiest way to tell the difference between diatoms and dinoflagellates is to disturb them. If they clump together they are dinoflagellates. If they disperse like sand they’re diatoms.
Knowing the difference between diatoms and dinoflagellates is crucial in knowing how to handle an outbreak of either species. Learning to identify the difference between species using the paper towel technique and treating the algae types individually is important to keeping your aquarium healthy.
That brown substance isn’t waste despite what you might think. It is more likely than not wither diatoms or Dinoflagellates spreading throughout your reef aquarium and knowing the difference should affect how quickly you deal with the nuisance and the method that you choose to do so.
Both species have different reasons for their presence within an aquarium but will spread across sand, glass, and live rock to thrive.
Though the two might seem similar to one another at first glance, the two species are actually quite different.
Diatoms are a type of algae that thrives off of excess phosphates, nitrates, and silicates in your water.
Dinoflagellates, on the other hand, thrive in nearly the opposite conditions. They can begin to overpopulated a tank that has sterile-like conditions.
So, say you thought the problem was diatoms and chose to perform a water change to help deal with the water parameters. Well, if it turned out to be dinos, you just helped to make the aquarium more sterile and helpful for the growth of their population in your system.
There are several differences between the two species. Even though they both just look like gross algae in appearance, they have radically different needs and can have a huge difference on your reef aquarium and its inhabitants.
Dinos thrive off of sterile environments and can produce toxins that are bad for different members of your aquarium. Your fish, coral, and snails can all be in danger with a dino population that is out of control
Diatoms meanwhile require more nutrients in the form of the presence of phosphate and nitrate to thrive as well as silica. Diatoms are not toxic but can throw off the parameters of your aquarium causing an issue for the entire ecosystem if not properly handled.
As bad as both seem, in low numbers, they can both provide benefits to your reef aquarium.
Dinoflagellates are a type of protist. What that means is that they technically can act like a plant and an animal; however, with our eyesight, we normally just see them as something more akin to algae. They use photosynthesis to grow and they can eat protozoa. There are hundreds of different kinds of Dinoflagellates but many are similar to one another.
Let’s be very clear. You want good Dinaoflagellates to be present in your tank in a moderate population as they can help fulfill one of the first rungs in the food chain. However, if aquarium parameters aren’t ideal, the once helpful species can quickly become nuisance algae.
On the other hand, some species are just nuisance algae that spread too quickly to be any benefit to an aquarist.
Yes, they can and will especially if they are the highly toxic Ostreopsis.
Yes, dinos can kill coral, unfortunately. This is another reason why it’s imperative to recognize the signs of a dino infestation and quickly act to get it under control.
The best way to identify Dinoflagellates (dinos) in your tank is to siphon a sample out of your tank into a small see-through container, preferably with a lid. For an easier sample, you can always use a turkey baster to try and grab a few specimens. Shake the container and finish by filtering the water through a paper towel. Once the water is seemingly clear again, leave it alone for about an hour and if it is a type of dino, then evidence of dino will begin to appear again.
Once you know that it’s a dino, you can begin to investigate its physical characteristics to determine what specific type it is.
You know that it is becoming a problem based on the appearance of your tank. Look for brown-looking lime in high-flow areas or areas that are well lit. Are some of the inhabitants of your tank dying? How are your snails and other invertebrates? Check your pH and if it is low for seemingly no reason, there is a potential that dinos could be the cause.
The type of dino you have in your reef tank can make a huge difference in your reaction to it. Knowing which species is present should dictate how quickly you start to resolve the problem like Ostreopsis. These four common types of Dinos might appear in your tank and being familiar with.
They all have slightly different appearances and they all share some characteristics so don’t let one species confuse you for another. These four dinos all produce air bubbles in the tank while also trapping some of those air bubbles between their slimy body and the glass of the tank. This can be a useful way to narrow it down that the brown algae-like substance you are seeing are dinos.
Dinos are a type of single-celled organisms that comes in several species that can accumulate in your reef tank. Though low amounts of dinos are to be expected in a healthy tank, the problem becomes when highly toxic types are present or the total population is out of control.
Technically, they aren’t conclusively algae but many people call them algae anyway due to their brown appearance. Since most aquarists don’t want brown algae in their tanks, lumping both groups together under the umbrella term as it’s mostly used to quickly reference that there is some brown plant-like material in your tank you are trying to rid yourself of.
Like we have briefly discussed till now, dinos are a good thing to have in a healthy tank as they are one of the first pieces of the food chain. The problem is when they aren’t kept in check properly and get out of control, which happens when the tank is nearly sterile. A sterile tank has few nutrients present in the tank, so few to no fish, little food intake, etc.
Dinoflagellates will eat a wide assortment of organisms including other dinos. They will eat diatoms and some will eat larger species like algae or zooplankton. They can become a huge disruption to your tank’s ecosystem if they are allowed to get too far out of hand.
As long as light and food sources are abundant for the dinos, they will be doing their best to stick around as long as possible. Chances are you are going to need to change something about your routine or manually remove the pests to get rid of your dinos.
If you do have a take where the dino population is out of control, it will be important to consider a few things before you try to eradicate them. Different methods will be more effective for different outbreaks and some may pose problems for your tank’s inhabitants if you aren’t careful.
The first thing you want to do is try to manually remove as much of the algae mucus substance as possible. The best way to do this is with a filter sock which will catch the dinos easily. While you are trying to deal with the dinos in your tank, you might consider introducing carbon which will help to negate the effects of the toxins that the dinos give off.
You don’t want to simply change the water of your tank or other common cleaning methods that you might try for other species of algae or water parameter problems. Remember that dinos love environments that have a lack of nutrients and nothing is better than a completely clean tank for them. This is why we want to take care of a few things before we start changing water and other care routine practices.
Increasing nitrates and phosphates is another method but be warned that with high levels of nitrates and phosphates other organisms and parameters can be affected. make sure you are not risking anything by following this method.
You can try a day blackout curtain or turning the lights off for around 72 hours. This will help to prevent photosynthesis which should keep the dinos from reproducing. Using the lights is a great way to help stop the dinos in their tracks but it will not remove them entirely. you will need to use other methods to remove all dinos from your aquarium.
Diatoms are another algae with a brown appearance and can cover everything in their ugliness.
Diatoms are not necessarily a bad thing but they are pretty unpleasant to look at in a tank. For most aquarists who spend hours upon hours trying to get the perfect look for their tank, the presence of the diatoms can really cause some frustration.
Diatoms themselves can’t kill fish but the overall effect that they may have on your water quality could end up hurting your fish. However, that would really only be in the case of a large bloom.
Corals are another story altogether since they are largely stationary most of the time. The diatoms can begin to grow around the coral and up their bodies and eventually kill them if given the chance. If you care about your corals and are beginning to see more and more diatom algae spreading throughout your tank, it is advisable to begin taking care of the problem.
Diatoms are fairly easy to identify. First, is it an ugly brown? next how easily are they removed from a surface? If you have to scrub hard to remove the brown substance from glass or other surfaces, it is likely diatoms. However, it could still be mistaken for dinoflagellates which is why you need to remove some of the substance and place it in a cup, shake it up, and strain the contents out using a paper towel. If the substances begin to come together again, it is likely a dino.
There are two groups of diatoms and they are really only distinguishable on the microscopic level.
Diatoms are algae with a brown appearance that more often than not appears after a tank cycle, though there is the potential for diatoms to appear later in the tank’s life as well.
Diatoms thrive off of the silicates that are present in some water. A good way to prevent diatoms is to use water that has little to no silicates present. You can achieve this by using water that has been treated with a RODI system.
However, silicates are not limited to the water source to enter your tank. Silicates can enter through salt mixes and substrates. The source of the silicates is even more important to identify than the fact you have diatoms in the first place.
As long as nutrients are present for the diatoms then they will persist. in most cases, you will need to do something on your part to remove them from your reef tank.
Luckily, you have some options when it comes to removing diatoms from your reef aquarium. Water changes should be near the top of your list, just make sure that you are indeed dealing with diatoms or you risk causing a bigger problem.
If you have a protein skimmer in conjunction with water changes to make sure it is running frequently to clean up the water as much as possible. You can also use additives to help cut down on the diatom population as well.
Knowing whether you’re dealing with dinoflagellates or diatoms is obviously critical to how you will deal with either problem. This exhaustive article hopefully has armed you with every detail you need to handle either outbreak and easily identify each.
Unfortunately, these aren’t the only problems you’ll deal with in a reef tank. If you’d like to continue learning about how to deal with common saltwater aquarium algae I recommend checking out our Reef Tank Algae article.
Join our list of interested reefers to get the latest updates
Also, don’t forget to follow us on Facebook, Twitter, & Pinterest
We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites
Content on Reef Tank Resource is copyrighted. Reproduction without permission is prohibited. All trademarks property of their respective owners.