Cyano with decent nutrient levels.

[CHSUB]

One of those studies that Hans-Werner provided demonstrated increased dinoflagellate growth in the presence higher dissolved CO2:

I didn’t see this….great find. J Sprung writes that increasing pH is an effective treatment for dinoflagellates. I’m wondering if it’s not the increase of pH but the lack of co2 which may show an increasing pH?

 

[CHSUB]

Our aquariums and the sea are different in many ways and most articles can’t be applied to our little systems.

While I will agree however imo they are not that different and I believe our success has only been achieved by closely mimicking the ocean. My example is before the hobby discovered using a big pile of rock as the primary means of stability. Each greater level of our success has more closely matched the ocean than the step before. I think the recent “step” of elevating nutrients is a misstep and doesn’t mimic natures blueprint.

 

[sixty_reefer]

While I will agree however imo they are not that different and I believe our success has only been achieved by closely mimicking the ocean. My example is before the hobby discovered using a big pile of rock as the primary means of stability. Each greater level of our success has more closely matched the ocean than the step before. I think the recent “step” of elevating nutrients is a misstep and doesn’t mimic natures blueprint.

Raisin Nitrate and Phosphate can be a safeguard for folks that don’t know how all the other nutrients are interconnected, Is not a bad advice imo.
It’s also not bullet proof as dinoflagellates also thrive in higher residual Nitrate and Phosphate in our reef tanks.


What not many folks cough on yet, is that dinoflagellates bloom as the conditions that thrive anabolism in heterotrophic bacteria becomes unbalanced in our reef tanks, there is multiple complex pathways in our system that depend on a constant supply of heterotrophic bacteria.

One of the largest differences between our tanks and the sea is that we can control more easily the nutrients in which we keep our corals.

 

[Randy Holmes-Farley Verified Community Expert]

One of my many reasons is here…the often quoted competitors that supposedly fail during low nutrient conditions are often also cited as prey.

Maybe. But the competitive hypothesis between diatoms and dinos is demonstrated in the scientific literature and in reefer aquaria.

The ubiquitous diatom Phaeodactylum tricornutum and dinoflagellate Prorocentrum minimum were cultivated semi-continuously, provided with different N and P concentrations (three different levels) and ratios (10:1, 24:1, and 63:1 molar ratios) under three temperatures (12, 18, and 24°C). The responses of diatom-dinoflagellate competition were analyzed by a Lotka-Volterra model and quantified by generalized linear mixed models (GLMMs) and generalized additive models (GAMs). The changes in nutrient concentrations significantly affected diatom-dinoflagellate competition, causing a competitive superiority of the diatoms at high nutrient concentrations, independent of temperature and N:P supply ratios.
https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2021.731786/full

 

[Randy Holmes-Farley Verified Community Expert]

I didn’t see this….great find. J Sprung writes that increasing pH is an effective treatment for dinoflagellates. I’m wondering if it’s not the increase of pH but the lack of co2 which may show an increasing pH?

Yes, that was the only treatment that was discussed decades ago. I wrote about it here:


Problem Dinoflagellates and pH by Randy Holmes-Farley - Reefkeeping.com

 

[CHSUB]

Maybe. But the competitive hypothesis between diatoms and dinos is demonstrated in the scientific literature and in reefer aquaria.

The ubiquitous diatom Phaeodactylum tricornutum and dinoflagellate Prorocentrum minimum were cultivated semi-continuously, provided with different N and P concentrations (three different levels) and ratios (10:1, 24:1, and 63:1 molar ratios) under three temperatures (12, 18, and 24°C). The responses of diatom-dinoflagellate competition were analyzed by a Lotka-Volterra model and quantified by generalized linear mixed models (GLMMs) and generalized additive models (GAMs). The changes in nutrient concentrations significantly affected diatom-dinoflagellate competition, causing a competitive superiority of the diatoms at high nutrient concentrations, independent of temperature and N:P supply ratios.
https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2021.731786/full

I’m going to toss most of the hobby observations in reef aquaria regarding dinoflagellates as I believe it is unreliable. The scientific literature can imo give a blueprint on how to successfully run a reef aquarium. Following the posted study, at reef aquarium temperatures, it appears to me dinoflagellate have a competitive superiority at higher nutrients and higher temperatures.

‘effect amplitude of nutrient concentrations varied with different temperatures, showing a switch back toward a competitive superiority of the dinoflagellates at the highest temperature and at very high nutrient concentrations’

 

[CHSUB]

Yes, that was the only treatment that was discussed decades ago. I wrote about it here:


Problem Dinoflagellates and pH by Randy Holmes-Farley - Reefkeeping.com

Probably read this back in the day and used it as model of operation. I recently purchased a microscope and confirmed dinoflagellate in my aquarium, however they like all nuisance algae have not been a problem since I learned how to properly clean an aquarium.

 

[Hans-Werner]

When was the last time a hobbyist had a red tide? I have never once seen a picture of a tank turned red with suspended dinos.

A tank with a dino "red tide" doesn't turn red (maybe "red tide" was named after the red cyano Trichodesmium?) but brown. You can't look into the blooming tank for 10 inches. I had planktonic dino blooms several times, proven with microscopes. The only way to get rid of them seems a UV-sterilizer.

‘effect amplitude of nutrient concentrations varied with different temperatures, showing a switch back toward a competitive superiority of the dinoflagellates at the highest temperature and at very high nutrient concentrations’

There are several studies that say that at low phosphate concentrations dinos have competitive advantages and, just as important, are much more toxic, killing snails, sea urchins, maybe hermit crabs and maybe fish in a tank. This is a physiological characteristic and these toxic dinos will show it everywhere, no matter whether in a tank or in a coral reef. Prorocentrum lima is one of these toxic dinos and it is one of the benthic dinos most frequently found in reef aquaria.

Ostreopsis looks similar to Prorocentrum lima, is also reported from reef tanks and may even produce Palytoxin.

Then you generously overred, that it is a "switch back" also occuring at low nutrient concentrations.

0.02 ppm phosphate is in the natural range in reefs. I wouldn't label it a very high phosphate concentration, in contrast to the usual nitrate concentrations in tanks. At 0.02 ppm phosphate, SPS corals are hardly able to have net phosphate uptake.

You make some "exercises" to ignore most of the results and concentrate at the single half result you like.

 

[CHSUB]

Is not a bad advice imo

I’m not sure either way, aquariums can differ dramatically. So obviously good and bad can depend on the set up….what I’m convinced of is, regardless of nutrient levels, aquariums are filthy and even with vigorous maintenance and weekly WC my aquarium with undetectable hobby level nutrients is still dirty. Advice that includes turning off skimmers and less maintenance allowing a dirtying up of a system is a mistake. I see post constantly about torch corals suffer from BJD, high nutrients, and a hobbyist scratching their heads why? Seems clear that higher nutrients includes higher bacteria levels.

 

[Hans-Werner]

I see post constantly about torch corals suffer from BJD, high nutrients, and a hobbyist scratching their heads why? Seems clear that higher nutrients includes higher bacteria levels.

I saw BJD only with low phosphate and high N levels, in my opinion a problem of imbalance and low P levels.

Most bacteria (except cyanos, purple bacteria and chemoautotrophic bacteria like nitrifyers, but I guess you don't mean these) are heterotrophic and need organic carbon. Under otherwise "normal" nutrient concentrations this is the single nutrient that limits growth of heterotrophic bacteria. You can test this easily by adding ethanol or acetate to a reef tank.

N and P concentrations tell nothing about bacteria levels. Rather the opposite, heterotrophic bacteria are superior to corals and algae in phosphate uptake at low concentrations. Dinos may feed on bacteria under these conditions and get a competitive advantage in this way.

Advocates of high nitrate concentrations claim that their tanks begin to look dirty under low nitrate concentrations.

 

[CHSUB]

There are several studies that say that at low phosphate concentrations dinos have competitive advantages

I don’t disagree with the above statement, how I disagree is how this is applied to a reef aquarium using hobby testing and hobby observation.

You make some "exercises" to ignore most of the results and concentrate at the single half result you like.

Will disagree. I might highlight information I feel is important based on what I believe is the best way to manage an aquarium; which is clean as possible.

 

[Subsea]

As a marine engineer, filthy & dirty are too general to mean much to me. As a municipal waste water superintendent and a process engineer at Dow Chemical I am very familiar with activated sludge processes using bacteria.

I don’t agree with running reef tanks “as clean as possible”.

Bacteria are the microbial overlords in my ecosystem as well as Planet Earth.

 

[CHSUB]

N and P concentrations tell nothing about bacteria levels

Will disagree. High levels of no3 and po4 are the results of a dirty aquarium with higher than natural level of bacteria. Unless the hobbyist is dosing these nutrients specifically.

 

[Subsea]

I saw BJD only with low phosphate and high N levels, in my opinion a problem of imbalance and low P levels.

Most bacteria (except cyanos, purple bacteria and chemoautotrophic bacteria like nitrifyers, but I guess you don't mean these) are heterotrophic and need organic carbon. Under otherwise "normal" nutrient concentrations this is the single nutrient that limits growth of heterotrophic bacteria. You can test this easily by adding ethanol or acetate to a reef tank.

N and P concentrations tell nothing about bacteria levels. Rather the opposite, heterotrophic bacteria are superior to corals and algae in phosphate uptake at low concentrations. Dinos may feed on bacteria under these conditions and get a competitive advantage in this way.

Advocates of high nitrate concentrations claim that their tanks begin to look dirty under low nitrate concentrations.

Hans,
To add to the complication, let’s bring DOC exudates from coral and DOC exudates from algae into the discussion.

 

[sixty_reefer]

I’m not sure either way, aquariums can differ dramatically. So obviously good and bad can depend on the set up….what I’m convinced of is, regardless of nutrient levels, aquariums are filthy and even with vigorous maintenance and weekly WC my aquarium with undetectable hobby level nutrients is still dirty.

There is good dirt and bad dirt, good dirt called flocs will help keep dinoflagellates at bay, most likely a strong link to your current success in your ULNS.

Advice that includes turning off skimmers and less maintenance allowing a dirtying up of a system is a mistake. I see post constantly about torch corals suffer from BJD, high nutrients, and a hobbyist scratching their heads why?

There is a science behind making good floc and often allowing folks to just make their system more “dirty” will allow some success, being able to grow microbes that will create new food webs that can eventually compete with dinoflagellates directly and indirectly.

Seems clear that higher nutrients includes higher bacteria levels.

As Hans mentioned earlier higher residual N and P don’t translate to higher bacteria numbers.
It usually means the opposite regarding bacteria or not sufficient photosynthetic organisms the tank in order to balance import export of N and P as we have two main export methods in a reef tank for Nitrate and Phosphate.

 

[sixty_reefer]

Hans,
To add to the complication, let’s bring DOC exudates from coral and DOC exudates from algae into the discussion.

Potentially we could touch on how this carbohydrates start multiple food webs for many beneficial microbes.

 

[CHSUB]

There is good dirt and bad dirt, good dirt called flocs will help keep dinoflagellates at bay, most likely a strong link to your current success in your ULNS.

I had to look up floc, not a term I was familiar with. I will add that imo good and bad dirt are exactly the same, only difference is bad dirt is not utilized by some desirable aquarium inhabitant and accumulates only to be consumed by bacteria. If hobbyists removes excess dirt all is good dirt, imo. With regards to ULNS, I don’t consider my system ULNS only low in excess nutrients. If for example, I added a bio-pellet reactor or dosed vinegar to super charge bacteria making nitrogen or phosphate limited than I would consider that system an ULNS.

As Hans mentioned earlier higher residual N and P don’t translate to higher bacteria numbers

I’m referring only to no3 and po4 in an aquarium not dosing these nutrients specifically. Only way to get residual no3 is higher bacteria levels. In simply terms less waste equals less bacteria, if we clean detritus, waste before it is processed to no3 we have less bacteria, including the bacteria that breaks down no3 to n2. I continue going back to simplicity and follow nature…abundant real foods for all inhabitants including corals with excess being removed and the very little left gets consumed by algae to be eaten or removed again.

 

[Subsea]

Potentially we could touch on how this carbohydrates start multiple food webs for many beneficial microbes.

Very complicated indeed.

Carbohydrates/glucose/sugar/DOC all feed bacteria. Inorganic chemistry is straight forward, however organic chemistry and biochemistry is very complex. Several years back, when discussing these things with Randy, he made this statement about biochemistry:
“we sent a man to the moon 30 years ago, yet we can’t cure Cancer”.

 

[sixty_reefer]

I had to look up floc, not a term I was familiar with. I will add that imo good and bad dirt are exactly the same, only difference is bad dirt is not utilized by some desirable aquarium inhabitant and accumulates only to be consumed by bacteria. If hobbyists removes excess dirt all is good dirt, imo. With regards to ULNS, I don’t consider my system ULNS only low in excess nutrients. If for example, I added a bio-pellet reactor or dosed vinegar to super charge bacteria making nitrogen or phosphate limited than I would consider that system an ULNS.
I’m referring only to no3 and po4 in an aquarium not dosing these nutrients specifically. Only way to get residual no3 is higher bacteria levels. In simply terms less waste equals less bacteria, if we clean detritus, waste before it is processed to no3 we have less bacteria, including the bacteria that breaks down no3 to n2. I continue going back to simplicity and follow nature…abundant real foods for all inhabitants including corals with excess being removed and the very little left gets consumed by algae to be eaten or removed again.

To me ULNS is a high import high export of nutrients.
We could get a higher No3 and Po4 due to less photosynthesis, reducing light photoperiod in a refugium could be an example of this.
Reducing waste would reduce ammonia firstly, less ammonia will translate to less Nitrate being transformed from ammonia.

 

[sixty_reefer]

Very complicated indeed.

Carbohydrates/glucose/sugar/DOC all feed bacteria. Inorganic chemistry is straight forward, however organic chemistry and biochemistry is very complex. Several years back, when discussing these things with Randy, he made this statement about biochemistry:
“we sent a man to the moon 30 years ago, yet we can’t cure Cancer”.

Bacteria uses doc in different ways.

Ethanol for example promote predominantly a catabolic process, it makes the bacteria respire Nitrate little goes to anabolic process in comparison to complex carbohydrates that will promote anabolism, meaning more nitrate and phosphate will be assimilated into their cell.

From what i read, in reefs most of the organic carbon comes from phytoplankton their decay promotes the formation of flocs (biological marine snow) that promotes heterotrophic bacteria cell growth via anabolism, this process feeds multiple food webs including free swimming and crawling ciliates; stalked ciliates; rotifers; nematodes; copepods and micro algae’s.
I believe the same happens in our tanks and most of the balance comes from this multiple food webs.