Deep Ocean Sump? Plankton in Our Tanks? Redfield Ratio? Many Qs!

[jzw]

ok, i must admit i'm posting this thread here, since it's very reef-nerdy lol

the recent r2r thread on "stirring up detritus as sps food" (https://www.reef2reef.com/threads/stirring-up-detritus-for-sps-food.413823/)

... got me thinking, usually a terrible thing. please chime in if you have knowledge of marine bio or oceanography, lol!

so many of us have heard about the nutrient rich waters of antartica, and the associated upwelling of nurients from the deep ocean. some of us have also heard of the existing principal oceanic gyre (the "great conveyor belt," aka thermohaline circulation), that help transport these nutrients. i assume these nutrients feed phytoplanktonic life forms, which in turn feed zooplanktonic life forms, and so on...




the reason i bring this up, is that deep, cold upwellings, be it from tides or currents, feed many of the world's riches reefs. i don't know from how deep or how cold, but when scuba diving in indonesia, you can really shiver when a chilly upwelling hits you.

question 1: what are these "nutrients" upwelled from the deep, is it detritus?

- are these nutrients organic, inorganic, or a mix?
- do we have similar detritus in our tanks?
- should we employ a 'deep ocean sump' and introduce that detrius occassionally?

we all assume that old sumps, with old established live rock (presumably with a lot of old detritus, and all sorts of bacteria and fungi) is a good thing, yes? for example, look at the video by oremium aquatics on sanjay's sump, i think sanjay said he's never cleaned it, ever. look at the video on reef raft usa, by LA frag guys. i'm sure tony intentionally hasn't touched that 'low flow' sump for years.

so this oceanic gyre thing, and these old 'do not touch' sumps, has me thinking about doing a separate sump that mimics the deep ocean, say 30 inches deep with low flow, with selected periods of high flow, to mimic our great oceanic conveyor belt. just extrapolating from my own little tank, there's gotta be an unimaginable detritus nutrient sink on the ocean floor!

as part of my arm-chair research, i read that as organic matter sinks to the bottoms of our oceans, and then anerobic bateria break down the organics into their inorganic constitutents (dosing inorganic nitrates and phospates comes to mind, but that's off topic here). true? if this is true, would dosing inorganics be shortcutting the anerobic processes that might occur in a 'deep ocean sump'? or is there something else in ocean bottom muck?

so that kinda leads to my next question, and apologies for quite the logic leap:


question 2. does anyone have a detectable amount of phytoplankton in their tanks (hobby, commercial, or institutional)?

- does anyone feed phytoplankton to their corals?
- do we want to maintain plankton in our tanks?

so our corals obviusly consume inorganics, such as Ca, Alk stuff, Mg, NO3, etc. then do coral also eat phytoplankton and zooplankton? i assume yes, at least size appropriate organisms. so just what are the zooplankton, like our anthropods, in our tanks feeding on? my 1 min crash course in marine bio, courtesy of wikipedia, says they eat phytoplankton. common sense says they feed on reef tank detritus because i believe nobody's ever measured plankton in a reef tank setting... true?

besides intoducing lifeform diversity and food for anthropod-a-vors and NPS, why is there maket demand for, say, algaebarn products?


3. what's up with the redfield ratio?

- are we growing corals, zooxanthellae, or phytopankton?

omg. someone clear this up. there's been a lot of talk about the redfield ratio lately. even brs mentioned it in a video. from what i understand on this rather old 80 year old ratio, all sampled biology, living and dead, in various oceans, conformed to this ratio.

C : N : P = 106 : 16 : 1

wiki says this has more recently been revised to 117:14:1

(i don't know if this only includes microscopic organisms, or also corals, fish and inverts.)

i read somewhere that deep water nutrients (detritus?) also very consistently follow the redfield ratio.

as a user of triton, i noticed they'll soon have a test for carbon and organics. are we all on a path to being plankton keepers? redfield ratio keepers? or is the redfield ratio totally bunk for our purposes, as 'surface' plankton take on the ratio of whatever chemistry they live in? or is this ratio somehow beneficial to all marine life on earth?

whew, off my chest. that's a lotta unknowns.

 

[WillB]

Awesome questions! I’ll be following along

 

[Brew12]

I love thoughtful questions! I'll take a shot at a few of them.

does anyone feed phytoplankton to their corals?
- do we want to maintain plankton in our tanks?

Yes, many of us feed phytoplankton. We all have phytoplankton in our tanks. If you look under a microscope, you can see phytoplankton in your system.

The reason we add additional phyto is due to the low quantities that we have in our tank. Phyto doesn't thrive on a reef, it gets consumed there. Unless you see people with green water (which does happen!) we just don't grow enough in relation to what is consumed.

are we growing corals, zooxanthellae, or phytopankton?

Yes, yes we are. It is important to establish conditions for all 3.

as a user of triton, i noticed they'll soon have a test for carbon and organics. are we all on a path to being plankton keepers? redfield ratio keepers? o

I feel that understanding the Redfield ratio is useful. Trying to do anything to maintain it is a fools errand. We only test for NO3 and PO4. The N: P ratio is all forms of nitrogen and all forms of phosphorus. We have no hobby level way to determine what are ratios are, so they cannot be controlled.

 

[jzw]

@Brew12

- do you maintain a phyto culturing set up? omg, please say no... not more crap to take care of!
and buying phyto on a regular basis is not feasible! actually, i've never seen any commercial coral place feeding phyto in the LA area.

- my system's always at zero NO3, so i'll be dosing inorganic NO3 on a doser soon. since everyone's NO3 is all over the place, and i so desparately need a target to start with -- my initial target will be the redfield ratio = (my icp result for PO4) x 10.5 (bulk reef supply video's mysterious multiplier for KNO3). should i do a separate thread on that lol?

i don't subscribe to the 'don't chase numbers' motto, except it makes me feel better lol! engineers chase numbers all the time, like calculating loads on bridges and their trusses, voltages and currents for chips n phones. imo, we'd be in the dark ages if we didn't chase numbers, or at least give it the good old college try.


***********


@everyone, please chime in on the contents of, and deep ocean muck biology!

 

[Sallstrom]

Great questions

Question 1
Nutrient rich water, upwelling, gets up to the surface(the photosynthesis zone) and turns into phytoplankton which feeds zooplankton and so on. So I think its nutrients from the bacteria breakdown of detritus in the bottom sediment that's counts as the upwelling.
Detritus can go under the name "marine snow" in the ocean. That's all the organic matter that sinks down from the light zone and gets eaten on the way to the bottom or when it reached the bottom.

/ David

 

[Brew12]

@Brew12

- do you maintain a phyto culturing set up? omg, please say no... not more crap to take care of!
and buying phyto on a regular basis is not feasible! actually, i've never seen any commercial coral place feeding phyto in the LA area.

- my system's always at zero NO3, so i'll be dosing inorganic NO3 on a doser soon. since everyone's NO3 is all over the place, and i so desparately need a target to start with -- my initial target will be the redfield ratio = (my icp result for PO4) x 10.5 (bulk reef supply video's mysterious multiplier for KNO3). should i do a separate thread on that lol?

i don't subscribe to the 'don't chase numbers' motto, except it makes me feel better lol! engineers chase numbers all the time, like calculating loads on bridges and their trusses, voltages and currents for chips n phones. imo, we'd be in the dark ages if we didn't chase numbers, or at least give it the good old college try.


***********


@everyone, please chime in on the contents of, and deep ocean muck biology!

I do not maintain a phyto culture. I don't feed it to my tank regularly, but I do add some every once in awhile.

I agree with you that some times we should chase numbers. I chase Alk, Calc, and Mg constantly.

NO3 and PO4 are a little trickier. Where the big 3 above are fairly constant, nutrients are continuously being cycled through the tank. Algae, coral and bacteria consumes it, waste decaying releases it. If you are growing large amounts of macro algae you can dose all the NO3 you want, unless you become PO4, carbon, or iron limited, you won't get detectible NO3. You will just get more algae.

 

[Sallstrom]

Question 2

Mostly speculations
I do not think there's lots of phytoplankton in our tanks unless we add it. We use skimmers and other types of filters that can remove small particles (like plankton).
Other thing is plankton is plankton. Plankton is organism that are bound to follow the current. E.g. Swim to slow to go against the current. We usually think of plankton as really small, but many jellyfish counts as plankton as well for example.
So they need the right current and conditions to survive and grow. In the ocean you often have a thermocline which divide water masses. So say if the thermocline is at 10 m deep, the water above is moving in the sunlit water every day. The phytoplankton gets enough light to grow and reproduce. So it's like a really big algae culture. But sometimes during a year the water is mixing and there's no thermocline. The phytoplankton will go to deeper water and don't get enough time in the sunlit zone, so the don't grow. That's one reasons for phytoplankton blooms in temperate water, the thermocline gets shallower in the spring and the algae starts to multiply because the stay in the shallow zone.
Water moves in circles in the ocean, so the plankton follows that circle. Hard to explain, but google waves in the ocean and there will be good illustrations I think.

So long story to get to my point I think our tanks are too small, and the most of the plankton end up on the bottom because they don't swim that good.

 

[jzw]

@Sallstrom oh, i finally get what you mean by marine "snow"

no way plankton can swim in my tank, there's so much flow the fishes get blown around hahahaha

@Brew12 so plankton equals no filter socks? i don't use them except when cleaning.

 

[jzw]

for some reason this pic didn't post in original

 

[Randy Holmes-Farley]

ok, i must admit i'm posting this thread here, since it's very reef-nerdy lol

the recent r2r thread on "stirring up detritus as sps food" (https://www.reef2reef.com/threads/stirring-up-detritus-for-sps-food.413823/)

... got me thinking, usually a terrible thing. please chime in if you have knowledge of marine bio or oceanography, lol!

so many of us have heard about the nutrient rich waters of antartica, and the associated upwelling of nurients from the deep ocean. some of us have also heard of the existing principal oceanic gyre (the "great conveyor belt," aka thermohaline circulation), that help transport these nutrients. i assume these nutrients feed phytoplanktonic life forms, which in turn feed zooplanktonic life forms, and so on...




the reason i bring this up, is that deep, cold upwellings, be it from tides or currents, feed many of the world's riches reefs. i don't know from how deep or how cold, but when scuba diving in indonesia, you can really shiver when a chilly upwelling hits you.

question 1: what are these "nutrients" upwelled from the deep, is it detritus?

- are these nutrients organic, inorganic, or a mix?
- do we have similar detritus in our tanks?
- should we employ a 'deep ocean sump' and introduce that detrius occassionally?

we all assume that old sumps, with old established live rock (presumably with a lot of old detritus, and all sorts of bacteria and fungi) is a good thing, yes? for example, look at the video by oremium aquatics on sanjay's sump, i think sanjay said he's never cleaned it, ever. look at the video on reef raft usa, by LA frag guys. i'm sure tony intentionally hasn't touched that 'low flow' sump for years.

so this oceanic gyre thing, and these old 'do not touch' sumps, has me thinking about doing a separate sump that mimics the deep ocean, say 30 inches deep with low flow, with selected periods of high flow, to mimic our great oceanic conveyor belt. just extrapolating from my own little tank, there's gotta be an unimaginable detritus nutrient sink on the ocean floor!

as part of my arm-chair research, i read that as organic matter sinks to the bottoms of our oceans, and then anerobic bateria break down the organics into their inorganic constitutents (dosing inorganic nitrates and phospates comes to mind, but that's off topic here). true? if this is true, would dosing inorganics be shortcutting the anerobic processes that might occur in a 'deep ocean sump'? or is there something else in ocean bottom muck?

so that kinda leads to my next question, and apologies for quite the logic leap:


question 2. does anyone have a detectable amount of phytoplankton in their tanks (hobby, commercial, or institutional)?

- does anyone feed phytoplankton to their corals?
- do we want to maintain plankton in our tanks?

so our corals obviusly consume inorganics, such as Ca, Alk stuff, Mg, NO3, etc. then do coral also eat phytoplankton and zooplankton? i assume yes, at least size appropriate organisms. so just what are the zooplankton, like our anthropods, in our tanks feeding on? my 1 min crash course in marine bio, courtesy of wikipedia, says they eat phytoplankton. common sense says they feed on reef tank detritus because i believe nobody's ever measured plankton in a reef tank setting... true?

besides intoducing lifeform diversity and food for anthropod-a-vors and NPS, why is there maket demand for, say, algaebarn products?


3. what's up with the redfield ratio?

- are we growing corals, zooxanthellae, or phytopankton?

omg. someone clear this up. there's been a lot of talk about the redfield ratio lately. even brs mentioned it in a video. from what i understand on this rather old 80 year old ratio, all sampled biology, living and dead, in various oceans, conformed to this ratio.

C : N : P = 106 : 16 : 1

wiki says this has more recently been revised to 117:14:1

(i don't know if this only includes microscopic organisms, or also corals, fish and inverts.)

i read somewhere that deep water nutrients (detritus?) also very consistently follow the redfield ratio.

as a user of triton, i noticed they'll soon have a test for carbon and organics. are we all on a path to being plankton keepers? redfield ratio keepers? or is the redfield ratio totally bunk for our purposes, as 'surface' plankton take on the ratio of whatever chemistry they live in? or is this ratio somehow beneficial to all marine life on earth?

whew, off my chest. that's a lotta unknowns.

Don't stress on the Redfield ratio. I'm not sure it has any useful meaning in our tanks. It's not a target level ratio, it's not a consumption ratio. I can't actually think how one would usefully employ it in a reef tank that has many other processes that use only N (denitrification, for example) or only P (binding to calcium carbonate surfaces).

The upwelling is mostly inorganic nutrients. Inorganic N, P, and Si are much, much higher in deep water than in surface waters where photosynthetic organisms compete for them.

 

[Scrubber_steve]

question 1: what are these "nutrients" upwelled from the deep, is it detritus?

- are these nutrients organic, inorganic, or a mix?
- do we have similar detritus in our tanks?
- should we employ a 'deep ocean sump' and introduce that detrius occassionally?

somewhat related; the Great Barrier Reef exhibit in Townsville Aust refers to two distinct periods in the evolution of its maintenance.
The “Oceanic Water period” (pre-2002) Average corals survival rate was only 20% to 30%.
The “Estuarine Water period” (2002 to present) corals survival rate increased to 70% to 80% (possibly higher now).

The difference being, they stopped using "priori ultra-clean oceanic water, collected offshore by barge", & instead starting using ‘less pure’ estuarine water collected on the incoming tide from the Ross Creek to increase nutrients and provide an external source of plankton.
They also removed all mechanical filtration from the system (three large sand filters) so the plankton wasn't stripped out of the water - so the corals could feed on it.
They also increased internal circulation, & started dosing calcium chloride to up the level from "~ 250 mg Ca2+.L-1, to 420 mg Ca2+.L-1)".

question 2. does anyone have a detectable amount of phytoplankton in their tanks (hobby, commercial, or institutional)?

- does anyone feed phytoplankton to their corals?
- do we want to maintain plankton in our tanks?
[/QUOTE]
I have a cryptic sump with sponges (& many other critters n thingys). I feed it continuum phtyoblast & brightwell sponge excell

 

[Brew12]

@Brew12 so plankton equals no filter socks? i don't use them except when cleaning.

I don't think it matters.

We have phytoplankton in our tanks, but in such small quantities it has little value. I am of the opinion that with or without filter socks, you cannot obtain a meaningful level.

Well, unless you run your system like a phyto culture, but that is a bit different.

 

[NY_Caveman]

question 2. does anyone have a detectable amount of phytoplankton in their tanks (hobby, commercial, or institutional)?

- does anyone feed phytoplankton to their corals?
- do we want to maintain plankton in our tanks?

A lot of smart replies here about this, but for some FWIW empirical data I offer some thoughts. I started a small aquarium about a month ago. 45 gallon AIO tank with about 35 gallons of actual water volume. I dose 5 ml of Phytoplankton (AlgaeBarn purchased) each day. In a small tank the store bought Phytoplankton lasts a long time.

It is a new build but I have some Palythoas that came in on the live rock and have tons of Copepods. The coral response to the Phytoplankton is obvious. Within 10-20 seconds of dosing, the Palythoas are closing up I assume because they are consuming the Phytoplankton. The pods are also going nuts and the coral may be catching some of them. This gets all of my shrimp and the one fish interested and then I feed them larger food after about 2 minutes.

EDIT: I feed during the beginning of my peak lighting period which is still quite low this early in the build.

 

[Scrubber_steve]

A lot of smart replies here about this, but for some FWIW empirical data I offer some thoughts. I started a small aquarium about a month ago. 45 gallon AIO tank with about 35 gallons of actual water volume. I dose 5 ml of Phytoplankton (AlgaeBarn purchased) each day. In a small tank the store bought Phytoplankton lasts a long time.

It is a new build but I have some Palythoas that came in on the live rock and have tons of Copepods. The coral response to the Phytoplankton is obvious. Within 10-20 seconds of dosing, the Palythoas are closing up I assume because they are consuming the Phytoplankton. The pods are also going nuts and the coral may be catching some of them. This gets all of my shrimp and the one fish interested and then I feed them larger food after about 2 minutes.

do you dose your phyto day or night?

 

[NY_Caveman]

I dose during peak lighting (which is pretty low right now as it is a new build). My feeling was if I dosed in the light I may get some Photosynthetic reaction and get a small benefit of nutrient removal as well.

 

[jzw]

somewhat related; the Great Barrier Reef exhibit in Townsville Aust refers to two distinct periods in the evolution of its maintenance.
The “Oceanic Water period” (pre-2002) Average corals survival rate was only 20% to 30%.
The “Estuarine Water period” (2002 to present) corals survival rate increased to 70% to 80% (possibly higher now).

The difference being, they stopped using "priori ultra-clean oceanic water, collected offshore by barge", & instead starting using ‘less pure’ estuarine water collected on the incoming tide from the Ross Creek to increase nutrients and provide an external source of plankton.
They also removed all mechanical filtration from the system (three large sand filters) so the plankton wasn't stripped out of the water - so the corals could feed on it.
They also increased internal circulation, & started dosing calcium chloride to up the level from "~ 250 mg Ca2+.L-1, to 420 mg Ca2+.L-1)"...

@Scrubber_steve, pictures of ross creek with commentary, nice!

this is a dumb question, but during their oceanic period, collected GBR seawater was THAT low in calcium? or rather that low in their tanks, after depletion. i guess you can't run barges 24/7 lol

 

[jzw]

@Randy Holmes-Farley, hi randy, it's not a target -- yet -- until it's marketed as one! (this thread is just maybe a half step in front of triton lol)

you see the NO3 dosing dilemma, right? my setup turned out to be an ULNS, so fortunately (or unfortunately), i must pick numbers to punch into the doser. besides redfield, do we have any other science-based, quasi-science based, or even reefer ratios? with reefers running successful tanks anywhere from above 0 to 50ppm NO3 , we have a giant range.

whoever said 'science produces repeatable results', surely wasn't talking about reefing ;Doctor. so are we in the 'art' stage of metallurgy, throwing stuff into smegma lol? not until we invent the NO3-PO4 redfield-ratio-director doser! haha.

heehee, i'm not too stressed about #s for my little tank, thanks randy. this is just a big group think.

but i am stressed that warmer weather in the northern ocean may be slowing down the great oceanic gyre ;Greedy reefers all know what happens when flow stops... just terrifying.

 

[Scrubber_steve]

@Scrubber_steve, pictures of ross creek with commentary, nice!

Thanks. I'm ok with photography with things out of the water, not so good with things in the water.

this is a dumb question, but during their oceanic period, collected GBR seawater was THAT low in calcium? or rather that low in their tanks, after depletion. i guess you can't run barges 24/7 lol
No, the calcium level of the ocean water was fine. The low calcium was depletion. I don't why they hadn't been dosing cal prior to 2002?

The low calcium was from depletion. I don't know why they didn't start dosing cal until 2002?

 

[Randy Holmes-Farley]

@Randy Holmes-Farley, hi randy, it's not a target -- yet -- until it's marketed as one! (this thread is just maybe a half step in front of triton lol)

you see the NO3 dosing dilemma, right? my setup turned out to be an ULNS, so fortunately (or unfortunately), i must pick numbers to punch into the doser. besides redfield, do we have any other science-based, quasi-science based, or even reefer ratios? with reefers running successful tanks anywhere from above 0 to 50ppm NO3 , we have a giant range.

whoever said 'science produces repeatable results', surely wasn't talking about reefing ;Doctor. so are we in the 'art' stage of metallurgy, throwing stuff into smegma lol? not until we invent the NO3-PO4 redfield-ratio-director doser! haha.

heehee, i'm not too stressed about #s for my little tank, thanks randy. this is just a big group think.

but i am stressed that warmer weather in the northern ocean may be slowing down the great oceanic gyre ;Greedy reefers all know what happens when flow stops... just terrifying.

Redfield might be a decent starting point for dosing both N and P if neither are detectable. Trial and error will tell you over time what ratio works best.

 

[Brew12]

besides redfield, do we have any other science-based, quasi-science based, or even reefer ratios?

We have eyes!

My experience, along with all of the research papers I have read, supports the following:

Phosphates dictate the total mass of biologics that grow. No phosphate, nothing grows. High phosphates can inhibit calcification but will encourage many other algae and bacteria to grow.

In low nitrate systems cyanobacteria do better. They can utilize N2 as a nitrogen source. In high nitrate system dinoflagellates tend to thrive. When things are right, and your CuC is eating the algae at the same rate it is produced, you end up with a nice clean tank.