Dinoflagellates in the Reef Tank - What, Why, and How?

Dino what?  Yeah that is what I said until I started looking more into the what, why and how.   I remember going to the beach with my parents one week for vacation and there were warnings everywhere.   The warnings were about the "red tide."   In fact I remember the water had a brownish red hue as the waves crashed into the shore.    It turns out that the red tide is caused by dinoflagellates, a type of single celled algae.   Some dinoflagellates produce a toxin that can harm marine life and humans alike.  Most of the time when humans get sick it is from eating seafood that has ingested the dinoflagellates, but some cases of sickness have occurred from breathing in aerosolized toxin or even skin contact.  Look up Ciguatera and you will hope you never eat any contaminated fish with this particular dinoflagellate toxin.

Just recently dinoflagellates were in the news as  a red tide is hitting San Diego beaches.   In this case the "red" is replaced by blue as the dinoflagellates are showing bio-luminescence at night. 

So dinoflagellates can be beautiful, but they are known for the toxins they produce.   So when these things bloom in your reef aquarium it can cause all kinds of problems!  Here is my story with dinoflagellates and I hope this story along with other stories can help those in the hobby.

It all started when I noticed my white sand in my tank was turning a thick greenish color.  After I read about it I thought I had identified what I had as cyanobacteria.   This is a bacteria that gets its energy through photosynthesis.   However it can take over parts of the aquarium and does not look very pretty.

There is a chemical called chemiclean that is supposed to do a really good job on cyanobacteria so I tried it.   I would speculate that an antibiotic is one of the main actives.   It worked really well and my green slime algae (cyano) was gone.

It was only a couple weeks later that my beautiful white sand was turning a brownish color.   I just thought it was cyano again since cyano can present as a brown, green, or purple color.   I did another treatment of chemiclean and this time the brown stayed.  The chemiclean did not touch it.  This is when I knew I was dealing with something else.  And it was only getting worse.  My entire sandbed started to turn brown.

I started to research and when you start looking at something that is brown and not cyano it is probably diatoms or dinoflagellates.  Diatoms are also a type of algae that usually bloom and then go away, so they are not usually a bad thing.  Dinoflagellates on the other hand are probably one of the worse things a hobbyist can get.  I started to panic a little.   This is also where I learned a valuable lesson.  Even with cyano I just treated based on some visual observations and a guess.

In hindsight I had another clue that I should have paid attention to.  Dinoflagellates also produce toxins.  Some produce more than others, but in my case I had ~75 small snails die very quickly.  Even the bigger snails would fall off the glass almost like they were drunk.  Look for these observations as well since it will help your identification.

In my case brown was mainly in the sand.  Some dinos will grow on your rock (and coral) as well and people will describe "snotty strands" of brown algae with bubbles coming off the rocks.  If you ever see that in your tank or hear that description, then dinos are a very probably cause. 

STEP 1:  USE A MICROSCOPE FOR IDENTIFICATION

Before you do any type of treatment, identification is so important.   Almost anything that happens in your aquarium can be treated if you have the right identification.  If you treat something without the proper identification you can do more harm.  Go to amazon or a store and buy a cheap kid microscope.  You can find these for under 20 dollars an it is all you need.  Here is one I found at a toy store.

I took a sample of my water and look under scope for the moment of truth.  That is when my heart sank.

I did not want to see anything moving, because the "flagllate" part of the dinoflagellate name means they have a flagellum.  A flagellum is a whiplike tail that lets it move.   And look at how many there are in just a drop of water!!

Once I realized I had dinoflagellates I needed to figure out what kind I have.  There are lots of types and as I would find out they all are a little different in how they should be treated.

I also realized that I was not the only one battling these things.  In fact dinoflagellates may be one of the few things that can happen to a hobbyist to cause them to give up and get out of the hobby.  There are so many stories of people getting out of the hobby or restarting from scratch because of these monsters.  This is because there is no easy fix.  Almost any other fish infection, algae bloom, or problem has a specific treatment or product.  Many of these products can fix a problem in days.   This is not so with dinoflagellates and I was about to learn that.   If you have these in your tank you need to read the forum over at REEF2REEF.  We are talking about hundreds of posts with help, but most importantly they can help you identify your particular dinoflagellate.  I cannot thank this community enough.

Read this thread!

https://www.reef2reef.com/threads/dinoflagellates-%E2%80%93-are-you-tired-of-battling-altogether.293318/

Here are the major dinoflagellates that hobbyist find in their tanks the most.  I took these pictures from the forums to help consolidate some info.

1.  Ostreopsis:  These are usually more sesame seed in shape.  They will move into the water column at night.

2.  Prorocentrum:  These are usually more oval, but can be rounder too.

3.  Coolia:  These are usually round and darker in color.

4.  Amphidinium:  The biggest sign you have this type is they will stay in the sand.  If your sandbed is the only thing affected and you have IDed dinoflagellates their is a good chance you have amhidinium.  This type comes in two versions, large cells and small cells.   Both seem to react fairly similar in the tank.

There can be other strains that may be in your tank, but these seem to be the biggest threats.  Many times you might have multiple types at the same time too which can make things even more difficult.

So once you have an ID the next step is to develop a treatment plan.  I had Amphidinium.   The identification came from how the cells look under microscope, the fact I was having a die off of snails, and the observation that the sand bed is what was mostly infected.

WHY DO WE GET THESE IN OUR TANK?

Before we get into treatment plans, why do you get these?  Well they are everywhere and there are probably already in your tank, but they just never bloom.  A bloom is where you will see them and they will start casing problems.

After reading the forums and and thoughts from other hobbyists the biggest reason I think dinos seem to bloom is because they do not have any competition.    I think there are two big reasons as to why dinoflagellates have no competition.

1.  Low phosphates and nitrates.   When I started my tank, my phosphates started to rise and I did everything I could to get them down.   When you have nitrates and phosphates get out of hand, you get all kinds of algae growing in your tank like hair algae or bubble algae.  We don't want that either.   So I added a GFO reactor and even an algae scrubber which eventually took my phosphates to almost 0.  I was very careful to not overfeed my fish and did not have a large fishload so my nitrates were also very low.  The problem is dinoflagellates have been shown to grow quite well in a low nutrient environment while other things do not.

2.  Low biodiveristy.  I have a hypothesis that in my case the chemiclean not only killed the cyanobacteria, but that it killed some other biodiversity in my tank.  Combined with the fact that I had low nutrients and then used chemiclean, I think I set up the perfect storm to let the dinoflagellates that were in my tank bloom.   There is one other connection I see when reading reports that affect biodiveristy.  Many hobbyist now use dry rock as opposed to live rock when setting up their aquairums for the first time.   The dry rock is "dead" when it enter the tank for the first time and slowly grows life, but only life that the hobbyist wants.  If we buy live rock we may be putting unwanted hitchhikers in our tank.   However the live rock is going to have a lot of biodiveristy.  I chose to use dry rock and I can argue that this may have been one more factor to start my bloom.

STEP 2:  TREATMENT PLAN

I did not really think through a treatment plan, I just started treating with anything that I saw worked for others.  I was getting desperate.   Here is what I did and what I learned in the process.  Those in green I feel had a very positive outcome in the end for my tank (amphidinium) and those in red not so much.

1.  Raise nutrients (nitrates and phosphates):  This is the first solution you will find on the forum about how to treat dinoflagellates.  It is counter intuitive to every thing you know and are taught, because dinos can use phosphate and nitrate to grow too.  However they seem bad at competing with other algae.  So this is step one of trying to get biodiversity back in the tank.  First I took my algae scrubber and GFO offline.  I stopped doing any water changes as I also did not want to replace used up micronutrients s or decrease the nutrients I was trying to raise.   I was targeting 0.10 ppm phosphate and 5-8 ppm nitrate.  To raise phosphates I added Seachem Flourish (phosphorus) and to raise nitrates I used spectracide stump remover (potassium nitrate).

Mix 1 part ro/di (1 us cup) with 1 part stump remover granules (1 tbsp). After I made a solution I did not need to add more that 5 -10 mL at a time to get an increase in nitrates.

 

 

This one is already in liquid form.   Again it took very little to raise phosphate for me.  However you need to keep measuring your nitrates and phosphates as it will take a couple weeks to stabilize.  Once you add them, they will get used up quickly.

 

 

I used a Hanna phosphorous checker to measure phosphates and the Seachem nitrates kit for nitrates. 

 



2.  Run Carbon:  I was already running carbon, but I started to change it weekly.   Even with carbon running I had a die off, but I am sure the carbon saved some of my fish and snails.

3.   Siphoning the sand:   I seemed to only have these things in the sand so i started siphoning the sand.  I ran the water through a filter sock and dumped the water back in the tank.   I may have slowed them down a little, but they just came right back.   I slowly stopped even trying this method. 

4.  3 day Blackout and hydrogen peroxide:  A guy at the LFS told me a three day black out might work along with adding hydrogen peroxide.   I had just started dosing nutrients and thought this might be worth trying.   You will see this method to control other algae blooms with success.  the idea is you cover you tank with blankets for 3 days.   The fish and coral will be just fine.  During that time and for a couple of weeks after I added hydrogen peroxide at the rate of 1 mL per 10 gallons of water.   The verdict is this did not work at all.  After the lights came on, everything looked pretty good, but the dinos immediately came back with a vengeance!

On a side note, I did some tests under the microscope and added hydrogen peroxide to a sample of my dinos.  They almost instantly died.    I just think that the amount of hydrogen peroxide I was adding to the tank was not strong enough to hurt their overall high population and any higher can start to hurt your coral.  Also the type of dinos I had were probably protected by the sand. 

5.   UV Sterilizer:  There are many reports that a UV sterilizer will work.  Many of the dinoflagellates will swim in the water column at night and the UV sterilizer will work.   Since amphidinium stays in the sand bed there are many reports that the UV will not help there, but I tried it anyway.  I bought a Jebao 55W UV sterilizer and hooked it up.  No luck for me with amphidinium.   However if you have the other types of dinos this seems to be a solution that is pretty dependable as long as you by one that is sized right.   Recommendation is at least 1 watt per 3 gallons.   I also plumbed this directly in the tank.  While it did not help me, for those species that it does work it seems having the pump directly in your display is better than in your refugium.   Again this did not work for me, but I put it yellow because I am certain its works on certain strains. 

--I PAUSED IN TREATMENTS TO RE-ACCESS  --

I had been raising nutrients for almost a month and if you do this you will go through a ugly phase.  I started growing green hair algae on my rocks and glass.  The dinos also got much worse.  If you go through this then I can say this is a good thing.   It did get to the point that it was starting to cover my coral in places so I would take a toothbrush and give these places a good cleaning. 

I finally hit a point after a month and half of dosing nitrates and phosphates where the tank looked awful.  Dinos and other algae were everywhere on the glass, sandbed, and rocks.   I got fed up with the way it looked and took a toothbrush to everything.  This actually increased my phosphates and nitrates even more.    My phosphates got as high as 0.20 ppm and my nitrates where 8-10 ppm.   I did this cleaning routine every other day for about two weeks and I them I hit a point where the algae did not start growing back and while the dinos were there, they did seem to be getting worse.   It was kinda crazy how everything just stopped growing.   I probably hit some limiting factor in the tank.  Many think this is iron, but maybe it is other things as well?  Something gets used up and dinos and algae alike do not grow as fast.   By the way I was not doing any water changes in this two month period either to replenish anything.

The good news is nothing was getting worse, but they were still there when I looked under scope.

5.  Add Biodiveristy:  After things got really ugly and I cleaned off everything, things were not getting worse, but not fully improving either.   I then also tried other ways to increase biodiversity.  I bought a bunch of FIJI mud (from BRS) and added that to the bottom of my refugium.  I bought a large piece of live rock and added that to my tank.  I bought 15 lbs of GARG grunge (course live sand) and added that directly over my sand.   I covered as much of the sand bed as I could with a thin layer.  Link: www.garf.org  I really feel like this garf grunge had a huge impact!!

5.  Silica dosing:  The last thing I tried was based on a paper someone had found on the forums.   It seems that silica has been used to initiate a diatom bloom and help out compete the dinoflagellates.  At this point things were doing better but again dinos were not completely gone.  Most samples still showed some in the sand, although much left after the garf grunge.  This silicate dosing was a strategy that seems like it is the most geared towards amphidinium since it stays in the sand. 

The paper is this one:  https://www.sciencedirect.com/science/article/abs/pii/S0044848602003733

I bought some silicate and started adding.   I did not do any calculations.  I just added 10-15 drops per day to my 125 gallon until I saw a diatom bloom. 

After about 2 weeks I got a good diatom bloom.  Everything got covered in brown including the sand, the glass and the rocks.   I was worried I actually had diatoms again, but I took a sample to see what was going on.

This time I had rice shaped diatoms and not dinoflagellates!   I still could find some dinos here and there but not like it was.   It would be just one cell instead of hundreds and I really had to take a lot of samples to find them.

I stopped dosing silicate and let the diatoms run their course.  Even after a month of no dosing I still have diatoms in spots, but the overall bloom is gone.   I went back to water changes, and still the dinoflagellates did not re-bloom.  At this point I know I at least won the battle.

The only thing I have noticed is whatever limiting factor hit to get stuff to stop growing I think is still a limiting factor.  I still have no algae growth in my main tank even with high nitrates and phosphates.   I am sending a water sample to ATI just to see how my water looks after all this.


Things I did not try:

1.  For amphidinium some people slowly remove all their sand.  I wanted to try everything before going this route, but there has been some success stories.

2. There is one product that is supposed to help with Dinos called DINO-X.   I again was only going to use this as a last report.  Just going by reports only it seems hit or miss and there are some reports of it hurting coral.   I have no direct experience with this one.

LESSONS LEARNED

1.  Make sure you ID what you are fighting.  It really makes a difference in how you will treat and will make sure you don't make things worse.

2.  I will never run a ultra low phosphate and nitrate tank again.   In fact my phosphates stay between 0.10 and 0.15 and my nitrates are over 4.   I added chaeto to my refugium and all the algae seems to grow down there now.  I do not have any algae problems in the main display.  Everything tells you to get those phosphates to 0.  Nope.  I will never do that again nor will I ever recommend it.   One bout of dinos and you will change your tune quickly.

3.  Use the resources out there and share your experiences.  There is an unbelievable community that i have so much to thank for and I hope my story can help someone else in turn. 


HAPPY REEFING!  AND DON'T GIVE UP!