Dinoflagellates – Are You Tired Of Battling Altogether?

[ScottB]

I’m currently battling Dinos too. I’m trying to raise NO3 and PO4 by dosing brightwells neo-nitro and neo-phos. After a full week of dosing per directions, my numbers still remain 0. Directions suggest my system is carbon limited. Am I to dose a carbon source to try and get NO3 and PO4 to rise? Pardon my ignorance, but I always thought carbon dosing will reduce these numbers? Any suggestions on how to raise my nitrates?

Yeah that instruction confuses everyone. I get what they are promoting, but your current purpose is different.

Get PO4 up first. Dose much harder than instructions. Your rock and sand (aragonite) is binding the PO4 and will continue until it gets to a certain level of saturation. It will then be releasing some back into the water and you will quickly be able to dial back dosing. In my 300G system, it took 2 liters of DIY solution. YMMV.

Once you get a decent reading on PO4 24 hr after dosing, then start with the Neonitro. My experience was that this much quicker to rise.

 

[echopiece]

Yeah that instruction confuses everyone. I get what they are promoting, but your current purpose is different.

Get PO4 up first. Dose much harder than instructions. Your rock and sand (aragonite) is binding the PO4 and will continue until it gets to a certain level of saturation. It will then be releasing some back into the water and you will quickly be able to dial back dosing. In my 300G system, it took 2 liters of DIY solution. YMMV.

Once you get a decent reading on PO4 24 hr after dosing, then start with the Neonitro. My experience was that this much quicker to rise.

Great thanks, I will try more phos! It’s a 100 gal (volume) system. Should I double the recommended dose? Triple it?

 

[Gedxin]

I’m currently battling Dinos too. I’m trying to raise NO3 and PO4 by dosing brightwells neo-nitro and neo-phos. After a full week of dosing per directions, my numbers still remain 0. Directions suggest my system is carbon limited. Am I to dose a carbon source to try and get NO3 and PO4 to rise? Pardon my ignorance, but I always thought carbon dosing will reduce these numbers? Any suggestions on how to raise my nitrates?

Also fighting Dinos and dosing. It took me almost a full week of nightly dosing before I was able to see detectable changes in my tests. I'd recommend staying the course, possibly raise your dosing slightly, until you're getting detectable levels - then back off slightly while testing regularly.

 

[ScottB]

Great thanks, I will try more phos! It’s a 100 gal (volume) system. Should I double the recommended dose? Triple it?

If my Hanna ULR is still giving me zeros, I would easily double my dose without worry.

 

[r-nel]

If you want to do some manual removal while you await the 40 Watt, check out the "poor man's UV".
It is just clamping a bunch of filter floss in the tank.

thanks I'll give this a try.

 

[Yodeling]

For those who are having problems getting nutrients up, here’s a suggestion. A 3-4 day blackout, for me at least, proved to be very effective at knocking back the Dino’s significantly. But also, an unintended consequence was that NO3/PO4 shot up and stayed up for a long time, even after the blackout. My theory is that as the Dino’s die as a result of the blackout, they release high amount of nutrients back into the water. The change was so significant that I would have to stop dosing and start running Phosguard to stop PO4 from raising too much. The nutrient spike would occur on day 3 or 4 of the blackout. I also run UV, so it’s possible that the UV is contributing to the blackout effectiveness, but I’m not 100% sure.

 

[chema]

You will find in the document afew things then:
a) LC Amphids are most often found in combination with other specie
b) Over time, your specie can shift. This is common.

Amphids are the toughest to beat. But they are also the least damaging/toxic. They are just ugly.

Hi Scott: I have started to treat again against Amphidinium, following you recommendations. After reading your article and the posts by taricha I'm a little confused about the addition fo Na2SiO3. The final concentration to achieve is 0.5-1.0 SiO2 (as measured by Hanna Hi705) or 0.5-1.0 Si (the result of multiplying the Hi750 result by 0.467)?

Thank you

 

[ScottB]

Hi Scott: I have started to treat again against Amphidinium, following you recommendations. After reading your article and the posts by taricha I'm a little confused about the addition fo Na2SiO3. The final concentration to achieve is 0.5-1.0 SiO2 (as measured by Hanna Hi705) or 0.5-1.0 Si (the result of multiplying the Hi750 result by 0.467)?

Thank you

I am going to tag @taricha on this specific question. It was his post that I linked in the article regarding dosing.

 

[taricha]

After reading your article and the posts by taricha I'm a little confused about the addition fo Na2SiO3. The final concentration to achieve is 0.5-1.0 SiO2 (as measured by Hanna Hi705) or 0.5-1.0 Si (the result of multiplying the Hi750 result by 0.467)?

Thank you

the answer is "yes"

It doesn't much matter, I saw the onset of diatom growth in my system at 0.1-0.2ppm SiO2 and didn't see any difference in the growth when I ramped it up to 2ppm SiO2.
So in my experience a few tenths is enough to have growth, and as long as there is some available, the Si dosing is doing its job. Exact amount doesn't matter that much.

 

[chema]

the answer is "yes"

It doesn't much matter, I saw the onset of diatom growth in my system at 0.1-0.2ppm SiO2 and didn't see any difference in the growth when I ramped it up to 2ppm SiO2.
So in my experience a few tenths is enough to have growth, and as long as there is some available, the Si dosing is doing its job. Exact amount doesn't matter that much.

Thank you taricha. For the last week I have been keeping SiO2 above 0,5 mg/L. Let´s hope that is enough to raise the diatom population. The appearance of the brown layer on the sand has not changed but I'll do some microscopic observations today and see how is the ratio Amphis/diatoms.

 

[taricha]

Thank you taricha. For the last week I have been keeping SiO2 above 0,5 mg/L. Let´s hope that is enough to raise the diatom population. The appearance of the brown layer on the sand has not changed but I'll do some microscopic observations today and see how is the ratio Amphis/diatoms.

The idea is that with Si available, whenever a trickle of other nutrients comes in, the diatoms will compete for them with the dinos. Not an overnight shift or replacement, but a gradual continuous one that favors the higher growth rates of diatoms.

 

[ScottB]

The idea is that with Si available, whenever a trickle of other nutrients comes in, the diatoms will compete for them with the dinos. Not an overnight shift or replacement, but a gradual continuous one that favors the higher growth rates of diatoms.

Isn't it refreshing to come back to a thread where we discuss the science and experience of reefing? Fun!

 

[taricha]

Isn't it refreshing to come back to a thread where we discuss the science and experience of reefing? Fun!

Some people are into fish, others corals.

this is more my style....

 

[Miami Reef]

@taricha @ScottB

How do you prevent dinos?

 

[chema]

The idea is that with Si available, whenever a trickle of other nutrients comes in, the diatoms will compete for them with the dinos. Not an overnight shift or replacement, but a gradual continuous one that favors the higher growth rates of diatoms.

I agree that providing Si should allow diatoms to compete with dinos . However that does mean necessarily that they shall outcompete them. In order to be able to do that we would need data on growth rates of Amphidinium and the species and strain of diatom present in the tank.
For instance, some species of pelagic diatoms, such as Phaeodactylum tricornutum does not responds to an increase of available Si with a directly proportional increase in growth rate, but changing its morphology.

 

[ScottB]

@taricha @ScottB

How do you prevent dinos?

The short answer is competition. Every mature tank has some in it. They are no more avoidable than bacteria. In a stable biome, they are very marginal competitors. Instead, most of the surfaces are covered in some combination of film (bacterial or algae film), algae, diatoms, cyano, coralline, coral, etc etc.

If you starve out or poison (Chemiclean) the competition, the dinos spool up real quick as the scavengers.

*edit: forgot to mention diatoms

 

[taricha]

I agree that providing Si should allow diatoms to compete with dinos . However that does mean necessarily that they shall outcompete them. In order to be able to do that we would need data on growth rates of Amphidinium and the species and strain of diatom present in the tank.
For instance, some species of pelagic diatoms, such as Phaeodactylum tricornutum does not responds to an increase of available Si with a directly proportional increase in growth rate, but changing its morphology.

The good news is we have that info available.

"For the first time, three thermophilic benthic dinoflagellates (Ostreopsis cf. ovata, Prorocentrum lima and Coolia monotis) were isolated from Bizerte Bay (Tunisia, Mediterranean) and monoclonal cultures established. The ribotyping confirmed the morphological identification of the three species. Maximum growth rates were 0.59 ± 0.08 d−1 for O. cf. ovata, 0.35 ± 0.01 d−1 for C. monotis and 0.33 ± 0.04 d−1 for P. lima." - source

And the absolute most common diatom seen in reef tanks is this guy...
"A unialgal isolate of Cylindrotheca closterium (Ehremberg) Lewin and Reimann from the Newport River estuary was grown in f/2 seawater media under continuous saturating irradiance at 27C. ... Growth rates on day one in both experimental conditions exceeded 2.3 divisions per day."

And although it's hard to find published info on our problem large cell amphidinium, we do have a paper where a small cell amphidinium bloom in a shrimp aquaculture pond was thwarted by Si addition and subsequent diatom growth.

We do not need (nor do I believe it is true) for diatom growth rate to be proportional to Si. Diatom growth rate - for at least common types we see - is plenty high. We just need there to be some Si. If there is enough, there are diatoms present in (I believe) every system that can and will grow faster than our problem dinos.

 

[chema]

The good news is we have that info available.

"For the first time, three thermophilic benthic dinoflagellates (Ostreopsis cf. ovata, Prorocentrum lima and Coolia monotis) were isolated from Bizerte Bay (Tunisia, Mediterranean) and monoclonal cultures established. The ribotyping confirmed the morphological identification of the three species. Maximum growth rates were 0.59 ± 0.08 d−1 for O. cf. ovata, 0.35 ± 0.01 d−1 for C. monotis and 0.33 ± 0.04 d−1 for P. lima." - source

And the absolute most common diatom seen in reef tanks is this guy...
"A unialgal isolate of Cylindrotheca closterium (Ehremberg) Lewin and Reimann from the Newport River estuary was grown in f/2 seawater media under continuous saturating irradiance at 27C. ... Growth rates on day one in both experimental conditions exceeded 2.3 divisions per day."

And although it's hard to find published info on our problem large cell amphidinium, we do have a paper where a small cell amphidinium bloom in a shrimp aquaculture pond was thwarted by Si addition and subsequent diatom growth.

We do not need (nor do I believe it is true) for diatom growth rate to be proportional to Si. Diatom growth rate - for at least common types we see - is plenty high. We just need there to be some Si. If there is enough, there are diatoms present in (I believe) every system that can and will grow faster than our problem dinos.

Thank you for the references. I have reviewed them. As you mention, the work concerning dinoflagellates do not include Amphidinium. However the problem is whether the growth conditions are the same or similar in both works. The work by Ben-Gharbia et al present results on the growth of the three species of dinos when cultured in enriched sea water. I have not been able to find the composition of that enriched sea water because the original reference was published in a journal my university has no subscription. In the case of the diatom (C. closterium) the authors present results when grown in Guillard's f/2 sea water. Therefore, if the growing conditions are not the same it is difficult to compare results. The comparison of curves seems to indicate that dinos are slow growers when compared to C. closterium). However, if the culture media are different drawing conclusiones is difficult.

I have been taking samples of the sand in my aquarium for months. I have observed both dinos and diatoms (Amphidinium spp. and C. closterium) when Si ranged between 150 and 300 microg/L (Triton and ATI ICPs), but diatoms did not outcompete Amphidinium. Now I'm trying higher concentrations of Si. We'll see. Also, I'll combine keeping a relatively high concentration of Si with sustained addition of bacteria.

 

[taricha]

However, if the culture media are different drawing conclusiones is difficult.

true, but across multiple references and different growing conditions - our problem dinos tend to have growth rates close to the values quoted in the study above. Their strategy of toxins and mucus favors a different kind of existence than the fast-bloomers.
(One might reasonably speculate that large cell amphidinium with low toxins and little mucus might be closer to the diatom end of the spectrum on growth rate.)

That's one of the reasons that many find nutrient addition helps shift a system away from our problem dinos - they don't really reproduce much faster with additions of nutrients, while there are a lot of other organisms that can.

 

[PandorasChalk]

While I am certain this is dinos, I wanted to get another opinion. The past week I have been working on eliminating this crud from my tank. I have been doing the following the last three days:

• Keeping lights low with no whites and lowest blue (save for the pictures)
• Feeding frozen everyday to help raise Phosphate
• Dosing 1.4 ml of H2O2 before work (lights come on at 4:30 pm I leave at 6:30 am)

I am noticing daily less on the sand, but still getting this film. I took the following picture of a sample at work under a microscope. The cells were moving around and tumbling. I am assuming they are dinos, they almost look like Prorocentrum to me.



This is what the tank looks like right when lights come on:



This is the same spot 4 hours later:


Here is a video of the “slime”

Parameters from last three days, tank is 5 months old and 14 gallons kept at 78 F:

Date​	Ph​	Nitrate​	Phosphate​	Magnesium​	Calcium​	KH​
3/6/2022​	8.2​	2 ppm​	0.0 ppm​	1450 ppm​	450 ppm​	10 dKH​
3/9/2022​	8.2​	10 ppm​	0.01 ppm​	1450 ppm​	430 ppm​	9.6 dKH​

I know that’s a lot of stuff, but I guess my worry is if I am truly fighting dinos, or if I’m messing up. I do have liquid Phosphate on the way to help target raise Phosphate.