Theory on nutrient ratios and algae/bacteria

[Randy Holmes-Farley Verified Community Expert]

Thank you Randy, I need to work on my writing skills.

That was actually the main point I was trying to make.

If we are nitrogen limited we are more likely to grow cyanobacteria. We can either reduce the phosphates available to reduce cyano growth or increase nitrogen to allow algae to out compete the cyano. If we are phosphate limited we are more likely to grow dinoflagellates. We can either reduce nitrogen to reduce the amount of dino's growing or add phosphates to allow algae to out compete them. We can use visual clues in our tank to determine if our systems are balanced. If they are balanced and we still have these issues then it is likely we are missing a trace element such as iron or manganese.

I wasn't necessarily disagreeing with you.

 

[saltyfilmfolks]

Yup, it is only the availability that matters. Understanding the balance helps explain the impacts of hitting a limit on one or the other.

Lol. Again only need available. Not a balance.

I just found the term "good" and "bad" to be very unscientific. It seems like they are passing a moral judgement on the bacteria.

Not good in bad in science, only Is or is not.
Lol

 

[mcarroll]

some of my favorite reefers on this thread



bear with me here...hopefully this is useful and not considered out of place
(I had to talk myself into posting this at all)

----

balance

i don't really think anyone is incorrect so far

it might be more correct to say that organisms absolutely require a balance for optimal performance

but what we're leaving out is that the term "balance" actually implies a component of time

you will see something referred to as "nutrient history" in the literature

at the other end of the spectrum from "balance" you can look up deprivation studies on (e.g.) phytoplankton to see what they grow like under nutrient deprivation

organisms have some variable (down to the species or even individual level) ability to compensate for environmental variability of dissolved nutrients

but there are definite limits

for example, many organisms can bank up nutrients internally for future use when environmental levels may be negligible

like us growing fat through the spring and summer to prepare for fall and winter

but stored nutrients get used up "in hope" that there will be another flush of nutrients

if these organisms cannot access another flush of nutrients, then they will have to respond to the lack of nutrients somehow

responses are highly variable between critters

many favorable photosynthetic algae just die off in response

dino's and other unfavorable algae are "more assertive"

the response of an organism like bryopsis or coral can be even more complicated

redfield

so there is no "ultimate redfield-like target" for detectable nutrients that could be used for all tanks

but all of the stuff above (in the whole thread) is also true

we tend to think of "nutrients" as N and P

because a) we can test for N and P, so we're aware of them

and b) because they are often the first nutrients to limit the growth of our target organisms

but nutrients are not really that simple

on the low end of the redfield ratio, trace elements have gotten some mindshare as nutrients

but we can't test for trace elements

so the consesus has histroically been not to dose them

on the high end of the redfield ratio (the ratio should be 106 C:16 N:1 P:0.1-0.001 Fe.), C is potentially a bigger differentiator than any other nutrient

organic carbon

the carbon dosing + GFO (C+GFO) revolution is well under way at this point

C+GFO seems to be "the norm" in reefing now

that revolution was founded on fear of nitrates, phosphates and algae

it took off based on promotional articles over the years about dosing vodka, vinegar, and commercial carbon preparations

it took off in spite of the fact that we can't test for C

in spite of some facts science has known about how ecosystems respond to carbon saturation

in spite of some facts science has known about how ecosystems respond to nutrient removal

C-saturated environments tend to favor those that can compete the best for dissolved nutrients

bacteria have a size to surface-area advantage over other organisms when it comes to uptake of nutrients

carbon is their normally-limiting factor

C-limited environments tend to favor those that can "make their own" C

that's phytoplankton, photosynthetics in general

nitrogen or phosphorus tend to be their most common limiting factor

carbon saturated, bacterially dominant environments tend to favor harmful algae

harmful algae are (more or less) those that generate toxins

harmful algae are not limited to any one group – there are harmful cyano, dino, diatom, chrysophytes, etc

C-saturation combined with N- and/or P-deprivation (very often all due to eutrophication) is a very common set of circumstances in harmful algae blooms in the wild

the same

c:n:p

circumstances (thanks to C+GFO in many cases) seem to play out with very similar results in home reefs

as demonstrated by the amount of traffic on dino, cyano threads, etc

in a new tank with no established microbial diversity, elevated-C with "ultra low" (or artificially-lowered) nutrients is a combo that appears to routinely lead to dino's as well as other "pest" algae

the use of dead rock instead of live rock is a concurrent trend with C+GFO

it would be interesting to see someone starting a tanks under C+GFO conditions compare one tank started with live rock and another started with dead rock to see if dead rock (lack of diversity) is the real root cause.

 

[Brew12]

Thanks for joining in!

but what we're leaving out is that the term "balance" actually implies a component of time

Absolutely. The balance is just that and needs to have a time component. Nutrients added minus nutrients consumed/removed leaves nutrients remaining. In a dynamic system this balance is continuously fluctuating over time.

we tend to think of "nutrients" as N and P

because a) we can test for N and P, so we're aware of them

This may be the only thing I saw that I don't completely agree with. I like the concept, but we cannot effectively test for N and P. We test for NO3 and PO4 and try to relate them to N and P. I'm sure many people think that the Redfield ratio means 16 parts NO3 are conumed for every 1 part of PO4 and that isn't accurate.

But, like you said, it gives us something we can measure and try to make comparisons with as opposed to most trace elements which we don't understand at all and can't/don't test for.

in a new tank with no established microbial diversity, elevated-C with "ultra low" (or artificially-lowered) nutrients is a combo that appears to routinely lead to dino's as well as other "pest" algae

Agreed. So much biodiversity new systems lack work to keep nutrients both balanced and in check. If nutrients are being consumed by phytoplankton this can be consumed by many desirable life forms rather than turn into any type of pest algae/bacteria or even beneficial algae.

 

[MnFish1]

True, and most of the uptake is from what is available in the water. If one nutrient isn't available it can no longer take in the other. This creates an unbalanced condition allowing a harmful bacteria to thrive.

On a side note... harmful and non harmful bacteria are scientific terms. No joke. Most of the research I have read on this comes from studies on algae/bacteria blooms.

Isn’t all uptake from what’s in the water?

In a reef tank there are probably thousands if not more species of bacteria in the water growing at any time. I think it is impossible to manage this population using testing numbers. First there can be lots of one species of bacteria doing fine even if one of its limiting foods is low as long as there is a steady stream of that nutrient into the tank somehow. Second every time you add a piece of food scrape off some algae a snail dies a coral spawns etc. there is a release of nutrients into the water you can’t control.

I also done believe there are harmful and ubharmful bacteria unless you are talking about a specific application. Bacteria are bacteria. If you dump a hamburger in your tank you may soon have lots and lots of ‘unharmful’ bacteria causing a huge problem

 

[Brew12]

Isn’t all uptake from what’s in the water?

Yes and no. Since it is an aquarium, I guess all uptake is from the water. Some species of Dino's actually consume cyanobacteria. Are they getting it from the water? I guess that is a matter of opinion and really isn't important imo.

In a reef tank there are probably thousands if not more species of bacteria in the water growing at any time. I think it is impossible to manage this population using testing numbers.

It is almost impossible to manage bacteria strains. What we can manage is the available nutrients and biodiversity.

As an example, I've used both Vibrant and Fluco in my system. It crushed my biodiversity. Neither product in itself was bad, it was the amount of both that I used. While my bacteria are fine, my pod population still hasn't recovered. My bristleworm population is starting to recover along with my pods but neither are where they should be in a healthier system.

As a result the nutrient control is still difficult in my system. My nutrients either spike high or plunge to zero. It took a long time for @mcarroll to pound into my head what the problem was. That problem isn't bacteria or algae, I have plenty of both. It is that next level of organisms. The pods, worms, sponges, corals, and complex macro algaes. Everything is food for something. Either I artificially kill off the bacteria and algae to allow my NO3 and PO4 to rise, or the bacteria and algae consume it all. In a mature system it is that second level of life that consumes the bacteria and algae before it can consume all of the nutrients in the water.

Using mature live rock (not the crap that is just rock with something like biospira added and sold as live rock) provides this next level of organisms a head start in a tank. Using dry rock, such as what I did, means you are going to fight the uglies and nutrient swings until you can get that diverse marine life established.

 

[saltyfilmfolks]

Yes and no. Since it is an aquarium, I guess all uptake is from the water. Some species of Dino's actually consume cyanobacteria. Are they getting it from the water? I guess that is a matter of opinion and really isn't important imo.


It is almost impossible to manage bacteria strains. What we can manage is the available nutrients and biodiversity.

As an example, I've used both Vibrant and Fluco in my system. It crushed my biodiversity. Neither product in itself was bad, it was the amount of both that I used. While my bacteria are fine, my pod population still hasn't recovered. My bristleworm population is starting to recover along with my pods but neither are where they should be in a healthier system.

As a result the nutrient control is still difficult in my system. My nutrients either spike high or plunge to zero. It took a long time for @mcarroll to pound into my head what the problem was. That problem isn't bacteria or algae, I have plenty of both. It is that next level of organisms. The pods, worms, sponges, corals, and complex macro algaes. Everything is food for something. Either I artificially kill off the bacteria and algae to allow my NO3 and PO4 to rise, or the bacteria and algae consume it all. In a mature system it is that second level of life that consumes the bacteria and algae before it can consume all of the nutrients in the water.

Using mature live rock (not the crap that is just rock with something like biospira added and sold as live rock) provides this next level of organisms a head start in a tank. Using dry rock, such as what I did, means you are going to fight the uglies and nutrient swings until you can get that diverse marine life established.

Lol. Nobody wants to belive me about the Fiji mud. Or Garf.

Also my bristle won't population crashed like a year ago. No real impact that I've noted.

 

[chefjpaul]

some of my favorite reefers on this thread



bear with me here...hopefully this is useful and not considered out of place
(I had to talk myself into posting this at all)

----

balance

i don't really think anyone is incorrect so far

it might be more correct to say that organisms absolutely require a balance for optimal performance

but what we're leaving out is that the term "balance" actually implies a component of time

you will see something referred to as "nutrient history" in the literature

at the other end of the spectrum from "balance" you can look up deprivation studies on (e.g.) phytoplankton to see what they grow like under nutrient deprivation

organisms have some variable (down to the species or even individual level) ability to compensate for environmental variability of dissolved nutrients

but there are definite limits

for example, many organisms can bank up nutrients internally for future use when environmental levels may be negligible

like us growing fat through the spring and summer to prepare for fall and winter

but stored nutrients get used up "in hope" that there will be another flush of nutrients

if these organisms cannot access another flush of nutrients, then they will have to respond to the lack of nutrients somehow

responses are highly variable between critters

many favorable photosynthetic algae just die off in response

dino's and other unfavorable algae are "more assertive"

the response of an organism like bryopsis or coral can be even more complicated

redfield

so there is no "ultimate redfield-like target" for detectable nutrients that could be used for all tanks

but all of the stuff above (in the whole thread) is also true

we tend to think of "nutrients" as N and P

because a) we can test for N and P, so we're aware of them

and b) because they are often the first nutrients to limit the growth of our target organisms

but nutrients are not really that simple

on the low end of the redfield ratio, trace elements have gotten some mindshare as nutrients

but we can't test for trace elements

so the consesus has histroically been not to dose them

on the high end of the redfield ratio (the ratio should be 106 C:16 N:1 P:0.1-0.001 Fe.), C is potentially a bigger differentiator than any other nutrient

organic carbon

the carbon dosing + GFO (C+GFO) revolution is well under way at this point

C+GFO seems to be "the norm" in reefing now

that revolution was founded on fear of nitrates, phosphates and algae

it took off based on promotional articles over the years about dosing vodka, vinegar, and commercial carbon preparations

it took off in spite of the fact that we can't test for C

in spite of some facts science has known about how ecosystems respond to carbon saturation

in spite of some facts science has known about how ecosystems respond to nutrient removal

C-saturated environments tend to favor those that can compete the best for dissolved nutrients

bacteria have a size to surface-area advantage over other organisms when it comes to uptake of nutrients

carbon is their normally-limiting factor

C-limited environments tend to favor those that can "make their own" C

that's phytoplankton, photosynthetics in general

nitrogen or phosphorus tend to be their most common limiting factor

carbon saturated, bacterially dominant environments tend to favor harmful algae

harmful algae are (more or less) those that generate toxins

harmful algae are not limited to any one group – there are harmful cyano, dino, diatom, chrysophytes, etc

C-saturation combined with N- and/or P-deprivation (very often all due to eutrophication) is a very common set of circumstances in harmful algae blooms in the wild

the same c:n circumstances (thanks to C+GFO in many cases) seem to play out with very similar results in home reefs

as demonstrated by the amount of traffic on dino, cyano threads, etc

in a new tank with no established microbial diversity, elevated-C with "ultra low" (or artificially-lowered) nutrients is a combo that appears to routinely lead to dino's as well as other "pest" algae

the use of dead rock instead of live rock is a concurrent trend with C+GFO

it would be interesting to see someone starting a tanks under C+GFO conditions compare one tank started with live rock and another started with dead rock to see if dead rock (lack of diversity) is the real root cause.

Great Thread!!

You did miss my favorite word as of late:
Probiotic.

 

[chefjpaul]

Lol. Nobody wants to belive me about the Fiji mud. Or Garf.

Also my bristle won't population crashed like a year ago. No real impact that I've noted.

I do.

Best diversity added to my sterile dry rock lifeless dino infestation of glass water box was an order of fresh algae and seaweed from liveplants.com, some AF mud, and an algae barn pod subscription.
hired a professional cuc and dont chase those numbers, just dose some "nutrients" of a form when / if needed.

Tried the ULN, doesn't feel natural or fit my personality of the tank.

 

[MnFish1]

Yes and no. Since it is an aquarium, I guess all uptake is from the water. Some species of Dino's actually consume cyanobacteria. Are they getting it from the water? I guess that is a matter of opinion and really isn't important imo.


It is almost impossible to manage bacteria strains. What we can manage is the available nutrients and biodiversity.

As an example, I've used both Vibrant and Fluco in my system. It crushed my biodiversity. Neither product in itself was bad, it was the amount of both that I used. While my bacteria are fine, my pod population still hasn't recovered. My bristleworm population is starting to recover along with my pods but neither are where they should be in a healthier system.

As a result the nutrient control is still difficult in my system. My nutrients either spike high or plunge to zero. It took a long time for @mcarroll to pound into my head what the problem was. That problem isn't bacteria or algae, I have plenty of both. It is that next level of organisms. The pods, worms, sponges, corals, and complex macro algaes. Everything is food for something. Either I artificially kill off the bacteria and algae to allow my NO3 and PO4 to rise, or the bacteria and algae consume it all. In a mature system it is that second level of life that consumes the bacteria and algae before it can consume all of the nutrients in the water.

Using mature live rock (not the crap that is just rock with something like biospira added and sold as live rock) provides this next level of organisms a head start in a tank. Using dry rock, such as what I did, means you are going to fight the uglies and nutrient swings until you can get that diverse marine life established.

Yet that is theory as well. With no basis in fact. No offense to either of you. Maybe look at jurassic park lol nature will fill the niche. Whats missing will be filled with 'something' - thats why its impossible to say 'dose this' or 'keep this at such and such a level' and there will be no problem - because - there is so much variability from tank to tank. It seems to (stupid me) that this is also the problem with the newer 'systems' designed to manage all of this - with testing... but... thats another debate

 

[MnFish1]

I do.

Best diversity added to my sterile dry rock lifeless dino infestation of glass water box was an order of fresh algae and seaweed from liveplants.com, some AF mud, and an algae barn pod subscription.
hired a professional cuc and dont chase those numbers, just dose some "nutrients" of a form when / if needed.

Tried the ULN, doesn't feel natural or fit my personality of the tank.

And I had dinos, did none of those things and with blowing them off the rocks for a couple weeks daily they are gone. So - what does that mean?

 

[chefjpaul]

And I had dinos, did none of those things and with blowing them off the rocks for a couple weeks daily they are gone. So - what does that mean?

Nothing. Absolutely nothing.

Mine were cleared up almost completely before I added, mainly due to me growing more algae. And just simply wanting more biodiversity and critters, that didn't seem to thrive in this particular uln test.

 

[MnFish1]

Nothing. Absolutely nothing.

Mine were cleared up almost completely before I added, mainly due to me growing more algae. And just simply wanting more biodiversity and critters, that didn't seem to thrive in this particular uln test.

Right its so hard to know what effective and what is not...

 

[chefjpaul]

Right its so hard to know what effective and what is not...

Exactly.

I've started tanks with dry rock and bacteria before, never had cyano, dinos, major algae etc...
This time, yes.

One must just be "in tune" with the individual tank, to challenge a difficult situation

 

[saltyfilmfolks]

And I had dinos, did none of those things and with blowing them off the rocks for a couple weeks daily they are gone. So - what does that mean?

They were part of the natural bloom and die like most things in an aquarium. The ate themselves out of a job. Or out of silicates. Or ammonia. Stuff you find in new reefs.

Also, that sounds like diatoms.

 

[saltyfilmfolks]

One must just be "in tune" with the individual tank, to challenge a difficult situation

Bingo.

 

[MnFish1]

They were part of the natural bloom and die like most things in an aquarium. The ate themselves out of a job. Or out of silicates. Or ammonia. Stuff you find in new reefs.

Also, that sounds like diatoms.

definitely not - i did a lot of blowing lol

 

[chefjpaul]

definitely not - i did a lot of blowing lol

We also need to remember Randy's statement regarding every species uptake of these said nutrients varries, so that will in turn change the method of removal.

 

[Scott.h]

I've been struggling with this topic for awhile. It may be all correct, or wrong. It seems like every time I have it figured out something proves me wrong. The dumb thing is my newest system.. the one that was going to be perfect, non rushed, built with only the best equipment, all while being understocked with fish, is the one screwing with me the most.

There is definitely a missing link. Most likely something we've created by adding more stuff - gfo, carbon dosing, etc. it sure would be nice to have a better understanding scientifically.

I've tried to keep my ratio as close to redfed as possible throughout the last year. Daily dosing of both N and P. Assuming my testing has significant error that I can't see, of course. When my P gets lower then .01 my LPS show me by pinching. When it's much higher then .015 the tanks glass show me with a ridiculous amount of nuisance algae. So I do my best to keep it around .015. With redfield, that puts the need for N to be .24, which isn't realistic to keep, so I aim for .75 and figure if my P is a little higher (.02) I just deal with the glass.

So perfect right? It doesn't seem that way. Now I have cyano all over the rocks in the fuge. (Which use most plant growth led spectrum). Very very little cyano in the display, but my fear is that it will work its way into the display. The "why", id really love to know. No carbon dosing or gfo, obviously adding, not removing. Immature bacteria on rocks? Possibly, or maybe something else.

Great topic, I'm glad people can share their inputs and experience on this. I'd love to hear more.

 

[Brew12]

Yet that is theory as well. With no basis in fact.

There are plenty of publicly available scientific studies discussing nutrient uptake in regards to both dino's and cyanobacteria. Just because you haven't taken the time to find and read them does not mean that this discussion has no basis in fact.
https://kb.osu.edu/dspace/bitstream...on_the_Occurrence_of_Harmful_Algal_Blooms.pdf
http://www.tandfonline.com/doi/abs/10.1017/S0967026201003456
https://drum.lib.umd.edu/bitstream/handle/1903/11423/Li_umd_0117E_10168.pdf?sequence=1&isAllowed=y

I believe you should have public access to all 3 of these. Otherwise, let me know and I can post more. I've read through at least 20 of them and am sure I can dig up a few more with public access.

I've tried to keep my ratio as close to redfed as possible throughout the last year. Daily dosing of both N and P. Assuming my testing has significant error that I can't see, of course. When my P gets lower then .01 my LPS show me by pinching. When it's much higher then .015 the tanks glass show me with a ridiculous amount of nuisance algae. So I do my best to keep it around .015. With redfield, that puts the need for N to be .24, which isn't realistic to keep, so I aim for .75 and figure if my P is a little higher (.02) I just deal with the glass.

I strongly suggest you do not try to use the Redfield Ratio in this manner! It will cause all sorts of problems! The N: P ratio is not the same as NO3 to PO4. They do not correlate well at all. Another thing to keep in mind is that the Redfield Ratio only applies to phytoplankton. These nutrients are also consumed by corals, nitrifying bacteria, macro algae and many other life forms. The more complex and diverse the life forms in our systems are the more the total consumption of nutrients changes. Even intense lighting can cause the Redfield Ratio to shift from 16:1 up to 35:1. Dim lighting can cause it to drop to 5:1. The 16:1 is just an average of the mass he found in various oceans.

I hope people don't feel my intent with this thread was to encourage use of this ratio to maintain nutrients. That couldn't be further from the case. It was really to explain, using the N: P ratio, how deficiencies in certain nutrients can promote the growth of some problematic bacteria. I wouldn't worry about trying to maintain any specific ratio. If I had a cyano problem I would look at adding Nitrates. If I had a Dino problem I would consider adding Phosphates. If I had detectible nitrates and phosphates and still had a problem I would look at trace elements.