[34cygni]

Originally Posted by Molecular data and the evolutionary history of dinoflagellates

The importance of dinoflagellates in aquatic communities is hard to overestimate. They are ubiquitous in marine and freshwater environments, where they constitute a large percentage of both the phytoplankton and the microzooplankton, and in benthic communities as interstitial flora and fauna or as symbionts in reef-building corals, other invertebrates and unicellular organisms (Taylor, 1987).

Emphasis mine. Translated from Science, that means both mixotrophic ("flora") and heterotrophic ("fauna") dinos like to live in the little gaps between sand grains. In all likelihood, Shimek's identification of the optimal size of sand grains to maximize biodiversity in DSBs and the subsequent adoption of "sugar sand" as a standard in the hobby means many of us are setting up ideal habitats for benthic dinos in our tanks.

Originally Posted by Growth, Feeding and Ecological Roles of the Mixotrophic and Heterotrophic Dinoflagellates in Marine Planktonic Food Webs

4b. Trophic mode effect
The highest MGR [Maximum Growth Rate] of the HTDs [HeteroTrophic Dinoflagellates] is double the highest MGR of dinoflagellates growing autotrophically. Also, MGRs of small HTDs are much higher than those of similar sized ATDs [AutoTrophic Dinos]. Energy gain of small HTDs through feeding may be higher than that of small ATDs through photosynthesis. Also, enzymes involved in photosynthesis may lower MGRs of dinoflagellates and it is worthwhile exploring this topic. The range of MIRs [Maximum Ingestion Rates] of each HTD was 0.04-24.4 ng C per dinoflagellate per day, while that of each MTD [MixoTrophic Dinoflagellate] species was 0.03-7.0 ng C per dinoflagellate per day. Also, MIRs of HTDs were higher than those of similar sized MTDs (Fig. 5). Heterotrophic activity of HTDs (feeding and digestion) is likely to be higher than that of MTDs.

In other words, among planktonic species heterotrophic dinos eat more and grow faster than mixotrophic dinos. It's likely the same is true of benthic species. Perhaps we can recruit some to help us by providing them with a cryptic environment where they have the home court advantage.

Originally Posted by Life cycle stages of the benthic palytoxin-producing dinoflagellate Ostreopsis cf. ovata (Dinophyceae)

Several of the cells followed in this study were likely to have been cysts. The various forms included: 1) non-motile vegetative-like cells, also called thecate cysts; 2) ecdysal cells with the same shape as vegetative cells, known as pellicle cysts; and 3) round to elongated thin-walled cysts. All of these forms were detected inside threads of mucous and were viable for more than 6 months after their formation, consistent with the suggestion that those cysts could constitute an overwintering population responsible for bloom recurrence. Interestingly, only the mucilage-covered cysts survived in the samples, suggesting that the mucilaginous matrix acts as a protective coat

Emphasis mine. This suggests that an environment rich in heterotrophic bacteria and microfauna would reduce the reproductive success of ostis depositing cysts there, as the protective mucous layer would be eaten away and the cysts exposed.

For solaris11 and anyone else at your wits' end, it's a simple idea that wouldn't be too difficult to investigate: dinos love sand, so can we use that to lure them to their death?


Molecular data and the evolutionary history of dinoflagellates
http://www3.botany.ubc.ca/keeling/PDF/04dinosJS.pdf

Growth, Feeding and Ecological Roles of the Mixotrophic and Heterotrophic Dinoflagellates in Marine Planktonic Food Webs
http://hosting03.snu.ac.kr/~hjjeong/...%2045%2065.pdf

Life cycle stages of the benthic palytoxin-producing dinoflagellate Ostreopsis cf. ovata (Dinophyceae)
http://digital.csic.es/bitstream/102...post_print.pdf

Originally Posted by PorkchopExpress

i actually just got another bloom yesterday and now it's become apparent that every time i've had a bloom, the only thing i did the night before was dose Acropower amino acids...this time was no exception, i dosed a half a cap of Acropower and sure enough the next day i had a bloom...i remember when i first got dinos in the old tank i was dosing vinegar, Acropower, using chemicals like chemiclean to get rid of cyano - a whole bunch of stuff...i stopped everything except Acropower which i dose seldomly and now it appears if i dose too much of it i get a bloom

Of course, you're well aware that vinegar is organic carbon -- bacteria chow -- but most hobbyists probably think of amino acids as a nitrogen supplement... In fact, amino acids are almost as small and easy for bacteria to absorb as sugar or vodka or vinegar. The difference is that while those are, as I said, basically french fries (high energy, low nutrition) amino acids are very nutritious french fries. Think of them as combining the energy of sugar with the nutrition of nitrogen (the "amino" in amino acids is derived from the same root as "ammonia").

The mental model we have is that dinos start out eating P-rich bacteria and use surplus P to recruit cyano, which provides the dinos with N. If dinos can absorb amino acids, little wonder dosing too much would trigger a low-level infestation to bloom -- you're basically doing cyano's job and saving the dinos the time and trouble of growing their own.

But as I said, I don't know for sure that dinos can absorb DOC from the water. I think it's a safe bet that they can absorb small DOC molecules including acetic acid, ethanol, and amino acids, as heterotrophic dinos can do that, and mixotrophic dinos evolved from heterotrophic dinos, and some mixotrophic dinos have evolved back into full-on heterotrophs. Strong circumstantial evidence, and your observations certainly add to it, PorkchopExpress. Thank you.

Originally Posted by Montireef

The skimmate I dumped in the system was the full content of the collection cup after a couple of weeks working. It was warm and not anoxic since it was on a working skimmer blowing humid air all the time.

I put a drop from the bottom of the cup under the microscope to find lots of nematodes, cilliates of diferentes kinds, heterotrophic dinoflagellates (oxyhrris marina) and tons of bacteria (spiros and cocos). There was a whole ecosystem teeming with life.

Glad to see you, Montireef, and thanks for this ingenious recycling tip!

So you dosed with fresh skimmate? Interesting. Some details must've gotten lost in the shuffle when I read through the thread, and somehow I got the impression that you had left it sitting for a week or two.

Can you confirm that you kept your skimmer off after you dosed your system? I really hope you did, as I have constructed a fairly elaborate theoretical structure on a foundation of black snail poop...

Originally Posted by Quiet_Ivy

So you're theorizing that the 'dirty' method works not because the green algae outcompete dinos for nutrients, but because there's a concurrent bacterial or microfaunal bloom which outcompetes the farmed dino-bacteria for food?

I'm wondering if there's a synergy there that hobbyists can exploit. Ostis produce toxins to keep from getting eaten, and they ramp up their production of toxins to protect their bacteria farms as they begin to become victims of their own success and drown in the waste generated by their farms (many other dinos are sometimes toxic and sometimes not, so the idea that dinos modulate their toxin production to favor the growth and reproduction of their preferred food species might actually explain this strange variability seen in dino blooms both in the wild and in vitro). They're trying to hold off the effects of eutrophication, and the dirty method is all about eutrophy. Heavy feeding leads to the accumulation of decaying organic matter and rising nutrient levels -- that's almost a textbook definition of the phenomenon.

It's very tempting to make a connection between macro-scale eutrophication of an entire aquarium and the micro-scale eutrophication of dino mucilage. However, there's another dynamic at work here. Dinos evolved to have a competitive advantage in low nutrient conditions. Green algae evolved to have a competitive advantage when there's enough nitrogen available. That's why dosing inorganic nitrogen can tip a system from dinos to algae. The nitrogen generated by the dirty method should do the same thing.

And that's why I suggested to PorkchopExpress that he try the dirty method with his UVS off. If raising NO3 will tip a system from one type of primary production to another, will raising NO3 plus "dirt" (meaning organic detritus and all the associated microorganisms) tip it faster?

Originally Posted by Quiet_Ivy

I wanted to set up a more complex ecosystem than is possible in freshwater, and learn Stuff. It's definitely been a learning experience, though mostly not a positive one.

That describes my entry point into the hobby very accurately, as well, though my subsequent learning experience has been on the whole more positive than not.

Originally Posted by Quiet_Ivy

I think DNA may have the same situation I do; severe lack of biodiversity very low in the food chain. Perhaps lower than is usual with dinos? I look at a lot of algae posts on the newbie forum, and nobody with out of control algae seems to have dinos. (That said there was someone on Reef discussion today with suspicious dinos-or-cyano). Several people have had sucess adding pods, which may indicate that their infestation hasn't nuked all the organisms below pods.

Your intuition is correct, but to do that topic any sort of justice would require a long science lecture. Suffice to say that there's an unrecognized trophic level below the autotrophs -- the heterotrophic microbial detrivores -- that consists largely, though not entirely, of single-celled organisms that recycle nutrients from organic detritus. Without them, the photoautotrophs that we intuitively regard as the lowest level of the food chain would "starve to death" from lack of N, P, Fe, and other nutrients. This is why you sometimes hear organic gardeners talking about how they really grow soil, and the plants take care of themselves -- they're talking about feeding the detrivores in the soil that degrade organic materials and release nutrients for the plants.

The argument can be made that detritus is actually the very lowest trophic level on the food chain. Dead, inert organic matter from fish poo to driftwood. A certain fraction of biomass is made up of very large and complex proteins that resist degradation by enzymes -- which is basically how bacteria and fungi eat -- and this biomass is called "recalcitrant" organic carbon (...blackwater, and most minor discoloration of aquarium water in general, is recalcitrant organic carbon accumulating in the water, and at the opposite end of the spectrum are tiny, highly soluble, easily consumed molecules like sugars and amino acids that are called "labile" organic carbon). Dead biomass in general, and the recalcitrant fraction in particular, is generated faster than it can be recycled by the detrivores, with the excess being buried and processed geologically. This is the origin of fossil fuels, for example, and a 7000 year old deposit of "diatomaceous ooze" (mud consisting principally of the remains of dead diatoms) that accumulated at the bottom of an ancient freshwater lake in the Bodele Depression in Africa is the source of phosphorous-laden dust that sustains not only the Amazonian rainforest once thought to the be "the lungs of the world" before research showed that most of the oxygen the trees produce by day is consumed at night by decaying detritus on the forest floor, but also cyanobacteria in the Atlantic Ocean that are the actual lungs of the world.

Okay, sorry -- I'm slipping into science lecture mode. I'll try to rein myself in. I know my posts are ridiculously lengthy, but the problem with trying to explain this stuff is that everything is connected to everything else. I can't explain any one thing without talking about how it fits together with other things because the very fact that it does fit together with other things is the reason why the one thing is worth talking about in the first place, and pretty much the entire world is connected to the oceans in profound ways stretching back billions of years, literally to the dawn of life itself. Moving on...

There's an ecological rule of thumb that as you move up the food chain, each trophic level has about 1/10 of the biomass as the one below it. But the very lowest levels -- the reservoir of detritus and the microbial detrivores feeding on it -- are even bigger than that because the transfer of nutrients up to the next trophic level isn't as efficient. Thus, though individually tiny, collectively the heterotrophic microbial detrivores represent more than an order of magnitude more biomass than Earth's autotrophs, and I believe them to be severely underrepresented in a typical aquarium.

Originally Posted by Quiet_Ivy

My pods are actually doing well, I saw some of those snowflake hydroids and a couple of flatworms this morning.

Glad to hear your pods are hanging in there, but as I understand it, those snowflakes are actually part of the life cycle of small jellyfish -- I'm a pretend oceanographer, not a pretend marine biologist, so you'll have to ask somebody else for more information about them -- and of course flatworms are notorious pests in both FW and SW tanks. They're both indicators of a collapsed food web and a hypereutrophic environment. In other words, they're symptoms of how sick your tank is.

Originally Posted by Quiet_Ivy

It was started with dead sand, when I started the tank (also with dead rock) but I got cups of sand from 3-4 people. Begged some spaghetti, hair, bristle worms too. CUC was bristleworms, nassarius, cerith, astrea snails, a serpent star (he's still in there!), 1 red reef hermit (still alive too), collonista snails, 3 sexy shrimp. No snails/shrimp have survived.

This is good news. I would have been worried if your dinos had killed a highly biodiverse, Shimek-compliant sand bed.

Since you have an interest in fostering diversity at the bottom of the food chain, I must tell you that you adopted the wrong approach to reach this goal. A Shimek-style sand bed is all about tiny creatures living in the sand and coming out at night to feed your corals, but it's compatible with only a very limited set of livestock in a DT, as other species will eat the tiny creatures. In order to get around this limitation and put sand beds in display tanks, hobbyists have adopted a set of larger creatures that physically stir up the sand with their movement. This approach is incompatible with Dr. Shimek's original vision, as these creatures -- stars are particular offenders -- eat the tiny creatures in the sand and destroy the biodiversity that DSBs were conceived to foster. The absence of tiny creatures and the relatively rapid and effective burial of organic detritus by infauna drives these sand beds towards hypereutrophy and a very high population of heterotrophic bacteria. And since it seems that having a bunch of heterotrophic bacteria around is how dino blooms get started...

Trends in the hobby seem to have converged to create systems that are tailor-made for dinos: ULN is their preferred competitive environment, we're providing what is probably the ideal sort of sand for organisms that love sand, and then we fill the sand up with detritus and bacteria. If you build it, they will come.

Though as Dfee's experience shows, dinos can thrive in coarser substrates with larger interstitial spaces, as well.

Originally Posted by Quiet_Ivy

Do you suggest deliberately stirring it?

No. This is a bad idea in general -- it fixes nothing -- and you don't have a functioning CUC right now. Even skimmate dosing strikes me as potentially very risky with a tank as far gone as yours, but since the protists and nematodes in it are almost certainly bacteriovores and your sand is choked with bacteria and mucilage, it may be a risk worth taking. But remember what I said to DNA about the immune system of corals... The weaker your corals' symbiotes are, the weaker your corals' immune systems are.

If you wish to take action that's true to the original vision you had for your tank, consider converting to a Shimek-compliant sandbed. It could be your contribution to the thread: you've shown us dinos can kill a noncompliant shallow sand bed, but is the biodiversity of a proper Shimek sand bed a defense against them? Can you even get a diverse population of infauna established in a dino-infested tank with a sand bed that far gone? Those are interesting questions, and you can potentially answer both of them. Plus, it would be the perfect complement to what cal_stir is doing: he's working from the top down, trying to control dinos by increasing biodiversity in the water, while you'd be working from the bottom up, seeing if it's possible to control a dino outbreak from below with biodiversity in the sand.

Give it some thought.

Originally Posted by Quiet_Ivy

I'm still going back and forth on shutting my skimmer down.

It's a carbon sink, so probably best to leave it on. And if those little snowflakes really are jellyfish, for sure best to leave it on. In fact, the skimmate you've collected may be contaminated with their remains, in which case you should pour it down the drain.

Originally Posted by Quiet_Ivy

definitely learning

Me, too. That's largely the attraction the hobby holds for me -- I started out 5 or 6 years ago thinking DSBs and algae scrubbers were cool, and that was the beginning of a path that led me billions of years back in time. At this point, I even have a theory to explain the Ediacaran Fauna and the Cambrian Explosion.

That's not particularly relevant to reefing (except for this possible survivor of the Ediacaran biota) but here's something that refeers should probably be aware of given the bio-centric nature of the hobby.

Originally Posted by Adrnalrsh

I've had my skimmer cup full for a few weeks with the skimmer off. Wonder if I should give it a try?!?!?!

Montireef reported dosing 2 liters of skimmate into a 600 gallon system, one liter in the morning and the other at night. If my math is right, in imperial units that's the equivalent of 1 gallon of skimmate going into 1135.623 gallons of water, half a gallon in the morning and half a gallon in the evening, so call it a 1:1000 ratio and calculate your dosage accordingly. If you're uncertain, start with a smaller dose and see how everything reacts.

And everybody remember that we don't know if this works -- I may have constructed an elaborate, scientifically plausible theory to explain a one-off bit of random aquarium weirdness -- so if you try Montireef's probiotic anti-dino skimmate dosing, please report your results.