Nitrate vs Phosphate uptake levels - species specific ratios

[Samala]

Ok, now details on that graph pretty please. Conditions (light, water flow, number of mangroves, age of mangroves, how NO3 was quantified and delivered to the test tank, etc.) Without knowing all the information and design and the intention of the experiment that goes along with these results they dont mean anything.

>Sarah

 

[wong BANTEN]

You can cacth that link for detail.
the design is very simple,and No spesific flow, and Number of mangroves. Because there will lot of RULE thats make that data seems UNCORRECT. FYI, I did that methode for Two Years.
I have an article that compares the Mangroove relation with Different Wheater,MUD,and Element versus N and P absorbtion,...also the speed of grows.

 

[charlesr1958]

<a href=showthread.php?s=&postid=6184651#post6184651 target=_blank>Originally posted</a> by Samala
maybe thats an indication that they have had to evolve to live off of less nitrogen, becuase they are not well adapted to pulling lots of it out of the water column.. or.. better.. that they live in areas where nitrogen isnt in abundance. One of those explanations or others..


>Sarah

Actualy that makes a lot of sense to me. On the reef flats prior to the coral reef, it is nothing but macro algae with a band of sargassum kelp as well. Pick just about any species of macro algae and it can be found there....with one exception, no calurpa species at all. With nitrate and phosphate levels reading "zero" on my test kits, your above statement made me go...hmmmmm. I do see calurpa once in a great while, but it will only be a little sprig and looking like it is having a hard time, hardly worth the time it would take me to collect it. Although I have, and once placed into my aquarium system with its higher nitrate and phosphate levels, it took off like the weed it is know for being. While the other macro algae species just sat there with little growth. Once my nutrient levels approached the same level as the reef, the calurpa died while the other algae is still plugging away, but still at its slow growth rate. (compared to calurpa).

Chuck ( In the Philippines)

 

[morphriz]

Holy resurrected thread again..

 

[Plantbrain]

OKAY,
Now there was an original question posed and an example here, using a study to imply that we can get more PO4 uptake out our weeds to help a reef tank.

We want to use macros to remove PO4........
There are two main issues here:

1. The loading rate from the Reef tank
2. The lowest level you want of PO4.

Now if rate is the key,, the ratios really do not mean much for us.............
If you want the lowest PO4, then the rate might be your biggest issue, you want a mixture of macros, some that are really good at rate response changes of PO4, and then another species that can eaqt up the rest of very low levels of PO4.

Ideally, we'd want the fast higher rate response macro to just slow/stop growing vs melt, so Chaeto makes this a decent weed.

Then you need a weed that is about to grow well under lean levels of PO4.

We have issues measuring anything well at 10ppb.
Macros start to get weird down around that level.

So that's okay, the smaller noxious species can grow fine under 10ppb, so even testing with the best of the hobby(and even some Lab research methods) will not tell you if you limit PO4 for the microphytes.

But back to the issue at hand............
Rate..........if I have a weed that has a massive growth rate, thus PO4 uptake rate, even if the PO4 ratio is 2x less, but the growth rate is 4X more, I'll export more PO4 with the lower ratio weed.

You also need to take into account N efficiency as you depress the PO4, and also light intensity/use efficacy.

It's not this simple two box model here when dealing with growth rates and PO4/NO3 uptake.

Ease of care for the weed is another huge giant issue.........

I think folks obsess too much over nutrients and not enough with basic aquarium keeping skills(water changes, cleaning, pruning, scrubbing etc).

You cannot see the forest through the kelp..............

There is a strong temptation to use studies to support things you want to believe(ask Freud)..........and perhaps there is correlation..........
But do not believe everything you think.

Question everything.
Especially the really basic stuff.
Then design a test to see.
Hopefully it can answer your question with supportive results.
Then you have a much better understanding and one specific for your system of choice(aquariums).


Regards,
Tom Barr

 

[piquesegue]

After hearing Richard Harker's presentation at a SV-SEA club event (October), I decided to check out an article he was quoting that said that some macroalgaes have an uptake ratio of 200:1 Nitrogenhosphate

http://www.botany.hawaii.edu/Bot482/Kaneohe Bay algae N-P Larned Mar Biol.pdf


It was a real eye opener as to how these macroalgaes & marine plants function contrasted to how many people use them in their refugiums - each has their own specific ratio

With most reef tanks having very low nitrogen (like 1-2ppm) and even lower phosphate ( like 0.5ppm) it would seem that it would be in our favor to use species that have lower ratios, rather than the extremely high ones (200:1 is for one species of caulerpa, while 150:1 is the N ratio for another).

much thanks to Samala for giving a great presentation to the Delaware Reef Club last month and opening up my eyes to the wild world of Macro's

to all macro-fans,
I know this is quite old, but I was so disappointed not being able to read the PDF article that i decided to contact the University of Hawaii and soon got a kind answer (by the way, thanks a lot Alison!):
The document is now available at:
http://web.mit.edu/qhorn/Public/Reef%20Aquariums/Phosphorus%20articles/Larned%20Marine%20Bio%20132%201998.pdf
Well, i hope it is that one, cause i can't compare with the old link which doesn't work anymore.
Anyway, i'm quite sure it's the same, and i'm really happy it's available again! :frog:

 

[tajaba]

thankyou so much piquesegue for sharing that! I was a bit disappointed that the original is not available

 

[chema]

Thank's a lot!!!!

I have been searching for this paper for a long time since I read the reference in R. Holmes-Farley's manuscript on phosphate export.

 

[Subsea]

N ratios internally vs external levels are two very different things.

We know from FW and other plant studies, that rastios becuome an issue under limiting conditions, if you provide good conditions for growth, this will not occur.

If you limit the P and N a lot, you end up with Cyano often times.........
P can drive NO3 uptake, if the P is limited.

Plants/macros can concentrate certain nutrients vs their external environment.

Also, they may have luxury uptake, so the N dry weights have little meaning under those conditions.

Some diatoms can store enough polyphosphate to live for 100 generations. Macros are much less, but you stilol can see a huge storage ability.

Basically though, a ratio will not affect a plant/macro. It is the limitation that affects things.

I can have a PO4 of .2ppm, NO3 at 10ppm, or a .3ppm of PO4 and NO3 of 2ppm.

Plants will do fine in both cases if they are maintained at those levels.

It's generally easier for folsk to keep one higher and then monkey with the PO4, or have PO4 input from food etc mainly....

The two nutrients are dynamic.
the ratio itself have little meaning, NO3 and PO4 are very cheap to add to a tank, so it's not an issue of getting the most efficient use, it's more an issue of preventing a limitation. In the tank, we can enrichment the system easily, in natural systems, the ratio can infer/show a N or a P limitation.

Regards,
Tom Barr

This post clarifies some questions that I had on making a fertilizer cocktail. I think that I need more nitrogen. I have noticed some cyno bacteria developing in my macro lagoon. For me, cyno is my bioindicators for excess phosphate. If I add ammonia, then my fast growing Calurpa should begin removing phosphate from the water colume.
I like Calurpae Paspoides because of its lacy, delicate leaves like a palm tree. When it is growing fast, the tips are opaque to white. When fast growth is limited, I look to nutrient limited. I already have an iron rich substrate from Seachem. Because I have cyno growing, there is phosphate in the water.

Time to add ammonia.

 

[taricha]

Nutrients to grow Algae - micro, macro, anything but cyano.
Want to throw this here and pick yall's brains.
People fighting Dinoflagellate infestations typically connect the onset of dinos with the disappearance of algae (especially GHA) in their tanks, so many of us try to grow algae to beat back the Dinos. The mechanisms of how algae might beat dinos is debated (and the hypothesis itself isn't certain) but lets leave that to the side.
People with low-ish nutrient tanks want to grow algae - lots of it, often as much as possible as fast as possible. Adding insult, once the dinos grab a foothold, it gets harder to grow algae. It's not unheard of for people with dinos to complain that they can't grow algae despite their best efforts.
Anyway: Macros are great, Microalgae might even be better (GHA connection and all), but limiting cyano growth is also crucial. Cyano and the dino plague are tied to the hip in most tanks.
Example in my tank, I have worked my Nitrate up to consistently 10+ ppm (KNO3 dosing), and my Phosphate to 0.20+ ppm (Miracle Grow 4-12-4, N from about half ammonia/half urea - derived from ammonium phosphate, potassium phosphate and urea). Daily I've been adding 10ppm NO3, and 0.20ppm PO4 - the tested levels above are pre-daily-dose. Caulerpa growing great, Chaeto - great, film algae on glass - ok, Halimeda - ok too even though it's calcerous, filamentous microalgae (GHA) - none at all, red cyano - steady daily growth. I'm giving my tank a few hours a day of sunlight through the window.

What would you guys advise for target nutrient levels/ratios, forms of N, etc?

 

[Jone]

taggin,,good read