It’s no secret, I had a battle with dino’s that nearly brought me to the end of my marine keeping adventure, before I had even hit the one year in mark! During my battle, I wrote a few blog posts & even mentioned it in a couple of videos I had put on YouTube.

Dino’s first appeared in my tank in March of 2019, just three months after I had set the tank up. I had tried black outs, not feeding, over feeding, hydrogen peroxide dosing and adding a UV steriliser. This combination wasn’t without casualties.

I’m pretty sure the hydrogen peroxide was the main culprit for the casualties. They included, a flasher wrasse, a lawnmower blenny, a chromis, an anthia, a male clown, a scooter blenny and all but one of my corals. It was a hard hit!

It got to the point where I had all but given up, my tank was a mess, things were dying infront of me & I couldn’t do anything to stop it. You may notice, there were several months where there were no posts to this site, well, this is why! I hated my tank. I just wanted out!

So, what changed? Well, the Dino’s went away! I’m not sure which of the things I was doing finally got rid of them, but I thought I would share my full experience in one last post.

I have now been dino free for 6 months.

How did I get dinoflagellates?

The Dino’s appeared because I let the nutrient levels in my tank get too low while the tank was still very young. Nitrate and phosphate were all but undetectable in the tank, which is prime Dino territory.

My light cycle was also running for too long. I was running with whites from 6am to about 8pm, then blues only until 10pm. Dino’s thrive in light, that’s why when you wake up and see the tank in the morning, you will notice a reduction in the amount of dino’s (if you are unfortunate enough to encounter them!).

My tank was very young when I got the Dino’s. I think I probably added too much too quickly to the tank, and looking back at the video’s I had done, you can see just from the colour of the rock, how immature the tank was.

Black Out

The first thing I tried to do was a 7 day black out. I completely covered the tank and made sure it was light tight.

The results of the black out weren’t great. The dino’s did vanish, but within 7 days they had started to return. I tried a second black out, same thing. I don’t recommend this method as a cure, however it does significantly reduce the amount you have to deal with post-black-out.

Changing my lighting cycle

I changed my lighting schedule dramatically to help combat the dinos, this may have helped to reduce them, but it didn’t help my corals.

Blues onWhites onWhites offBlues off
Pre-Dino’s6am7am8pm10pm
During-Dino’s9am10am2pm4pm
Post-Dino’s7am8am4pm10pm

As you can see, while I was battling the dino’s I reduced the time I had my lights on, I have since increased the time the lights are on, and the dino’s have not returned.

I think not allowing the Dino’s to have lights, definitely helped with the battle.

Reduced Feeding & Over Feeding

Overfed Fish
It’s tempting, but just don’t do it!

I tried 2 weeks of each, over feeding and significantly reduced feeding of the tank. This produced absolutely no results. It didn’t seem to increase or decrease the amount of Dino in my tank, or the rate at which it was growing.

What it did do was send my nutrient levels in a spin, which resulted in very stressed fish & corals.

Dosing with Hydrogen Peroxide (3%)

I honestly think this is the thing that had the biggest impact on the Dino’s. When dosing, you could see the Dinoflagellates receding before your eyes, especially when target dosing to the worst effective areas.

3% Hydrogen Peroxide
3% Hydrogen Peroxide

BUT, I also think this is the main culprit for killing the livestock I had. I realise that Dino’s are poisonous to marine life, but I am pretty sure the peroxide pushed my, already stressed, fish & corals over the edge.

I mentioned in my video that Hydrogen Peroxide doesn’t just kill bacteria such as Dinoflagellates, it also kills the good bacteria. I don’t think I quite grasped that fully at the time of dosing because I was just desperate to get rid of them.

I think I killed all the good bacteria, which caused an ammonia spike, which in turn cause my tank to recycle and crash. It was my own fault that I lost my livestock, I shouldn’t have used such a high dosage of the peroxide to try and see faster results.

I think we all know, nothing good happens quickly in this hobby.

Would I dose it again, well, probably. If I was as desperate as I was when I started dosing it, I didn’t think I had any other choice. It was either the peroxide or the closing the tank down completely.

UV Steriliser

When the tank started to crash & fish started to die, I decided to take one last stab at the Dino’s by adding a canister filter with a UV steriliser in it.

I know canister filters can been seen as Nitrate factories in marine tanks, and I don’t think that is wrong, but I was at breaking point with my Dino battle. It seemed like a good option to be able to add and remove a UV steriliser quickly and easily to the system, without having to try and add a manifold onto my return pump.

I wasn’t wrong. It was quick and easy. It has increased the nutrient level in the tank, but it also helped combat any free-floating Dinoflagellates that were within the water column.

I give the UV filter a big chunk of the credit for helping me beat them. I still run the canister filter, along with a sump full of equipment, just because I am terrified that if I turn it off, the Dino’s will come back.

Other Resources

If you are struggling with Dino’s, rest assured, you are not alone & it is possible to beat them.

Since beating the Dino’s I have come across a very helpful group on Facebook, here >>> Dinoflagellates Support Group. If you are on Facebook, I would highly recommend joining this group. They have a “regime”, which many people have found success with.

For those of you not one Facebook, here are some of the documents available within the group. FULL credit goes to the admins of the group, with the regime credit going to Cruz Arias.