Dinoflagellates are a recurring problem in our tanks. I also had the plague in mine, and had to fight it for almost a year. On the internet many different approaches are described and so I have tried many potential solutions. I failed several times, and therefore I can understand that some people give up the hobby because of dinoflagellates.
It all began in late February 2012 with a slight rise of cyano bacteria. It didn’t seem that dangerous to me, because I have heard of emerging cyanos in spring time several times, that are caused by the changes in tap water and will probably disappear by themselves after some time. My actions then focused on selective vacuuming during water changes, because I’m not a fan of blind actions or the use of chemicals in the aquarium.
In mid of April, after my return of a two-week vacation the cyanos population had increased significantly. I kept vacuuming continuously….
In May it became serious. The cyanos disappeared and the dinoflagellates (dinos) came up.
Do dinos suppress cyanos?
Until then I had no experience with dinos, that’s why an observation phase of the plague for the next two to three weeks followed.
The first finding was that vacuuming didn’t help at all. Sunday afternoon at the regular water change I vacuumed the dinos intensively. On monday, there was a thick layer of dinos again.
I began to realize how fierce this plague is.
In early June I launched a daring attempt to vacuum the dinos on one hand, on the other hand not to add more fresh water. So I vacuumed ground intensively, then I filtered the extracted water through two layers of kitchen towels and gave it back to the tank. Thus I could reduce the dino population significantly for the moment and didn’t add new nutrients with new water (phosphate, silicate, etc.). This was a very time consuming task that unfortunately remained unsuccessful.
After the dinos were settled on the reef and coral I started to become nervous.
You could really see the corals the ‘pressure’ on the corals. The polyp expansion went back and the corals seemed weakened.
End of June, I opted for the use of PhycoEx in combination with a light reduction. First, not much happened, but after about a week I could see a decline of the dinos. After about ten days I stopped the medical application thus a coral was disintegrating. I mainly attribute this to the lack of the lowered lighting time.
But now I had achieved some (first!) small success. The dinos were still there, but the repopulation, after a water change and vacuuming, was significantly slowed. Nevertheless, after about three days the sand was covered again. But the reef was dino free now.
At the end of August I moved to my new apartment. I sensed that this could be a chance for the final blow. The movement went smoothly and without losses. Now I tried to run the pool without sand in the hope of being able to keep the settlement area as small as possible and vacuuming becomes easier. Unfortunately after a short time dinos were covering the ground glass so that nothing changed and I gave the new sand in the tank again.
In October I tried it, to raise the KH by the usage of Natriumhydrogencarbon to 8-9 in order to lower pH value into a higher alkaline range. There are suggestions that this could help, which did not apply to me.
Between Christmas and New Year I decided to start the usage of a silicate filter, which is connected behind the osmosis plant. Actually, I wasn’ able to detect silicate in my water, but I did not trust the available silicatetests.
In January, I was able to find a first change. There was a slight formation of slimy algae that could be vacuumed easily. At the same time I realized joyfully determined that the dinos went back.
In February, I was free of any disease after almost a year.
Summing up, I can trace my success only to the silicate filter. A dinoflagellate infection is really a serious and long-lasting contamination that is frustrating at some time. Now I can enjoy my plague free aquarium even more!