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Astonishing

Discussion in 'Algae Control' started by awrieger, Aug 19, 2005.

  1. awrieger

    awrieger Junior Poster

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    I switched to Tom's new 7:1 ratio of NO3:pO4 six days ago when I got the August newsletter.

    Tank - 35g, 3.4w/g.

    7 days ago, NO3 measured at 8, while PO4 was 0.5. A ratio of 16:1. Algae growing all over the glass. For weeks, persistently coming back within a day of scraping it off.

    6 days ago, tweaked the nutrients so NO3 is 14 and PO4 is 2 (just approximately, I wasn't being exact) and knock me down with a feather - not a single bit of algae growing on the glass for a week now. Not even a spot. It's still as clear as if the tank is new or freshly cleaned.

    Such a small difference to this ratio seems to have made such a large difference so quickly.
     
  2. Tom Barr

    Tom Barr Founder
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    Re: Astonishing

    It's still just an observation.......but, it's also one that many can confirm repeatedly.

    The main issue when comparing ferts and routines, make certain the CO2 is up and non limiting!!

    If you can do that, then you can really do well with testing a variety of routines.

    So would you say that high PO4, clearly excess PO4 causes algae or not?
    How did folks get things so wrong for so many years?

    That's really what makes me wonder.............even companies claiming research (the question is, who's research are they citing here.......) "shows" or was "done".

    Now see how the routine does 3-4 weeks from now.
    Make sure to prune.

    Regards,
    Tom Barr
     
  3. imatrout

    imatrout Prolific Poster

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    Re: Astonishing

    Same thing happened to me. I just cut back on KNO3 and left everthing else the same. Currently I'm trying to keep N between 6-8. Lo and behold, not a speck of algae!
     
  4. awrieger

    awrieger Junior Poster

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    Re: Astonishing

    It certainly is repeatable. I also adjusted the ratio in my 24g aquascaped tank at the same time. It didn't have the glass-growing algae as badly as the 35g, but still had enough for me to scrape of each week.

    The result is the same - not a spot of algae on the glass after a week. As I said, astonishing.

    But why? It's like having a loaf of bread and some turkey slices. You can grow big and fat and fast with any imaginable combination of the two - except! - but if you have exactly 7 slices of bread and 1 of turkey (or 14 and 2), then you'll die of malnutrition.

    I think that's the astonishing bit.

    I can't see how such a ratio can be maintained without constant testing of both though. If you're going by estimation, then an outbreak of algae could be either NO3 or PO4 going up or down, so how do you know which it is? Just testing NO3 doesn't tell you how much it is related to the PO4. You'd need to test both.
     
  5. awrieger

    awrieger Junior Poster

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    Re: Astonishing

    If you don't mind, I'm going to refer to it as the Barr Ratio if you haven't already christened it. 7:1.

    Technically then, any 7:1 multiple of NO3:pO4 will work. So even PO4 at 5ppm should not induce algae if NO3 is 35ppm.

    Perhaps the tests they did showing high PO4 levels inducing algae were done without referencing it to the NO3 levels, so in a sense they were correct, but they missed the crucial factor - eg high PO4 does induce algae IF it's not balanced by NO3, so in that sense they were way off-beam.
     
  6. defdac

    defdac Lifetime Members
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    Re: Astonishing

    If you always dose 7:1-ratio and do large waterchanges each with with good growth I can't really see why the ratio would change?

    If the input always is 7:1 a slight increase/decrease in PO4 xor NO3-uptake wouldn't matter in the long run.
     
  7. Tom Barr

    Tom Barr Founder
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    Re: Astonishing

    No, they simply never did any ratio work at all, nor added any PO4, they assumed any excess PO4 caused algae but also conceded that plants still needed PO4.

    A rather conflicting premise.......
    So they tried to add PO4 etc to the substrate.

    A similar thing and approach occured with NO3, until fairly recently when I started nagging about NO3..........

    Just like when I nagged about PO4......

    N:p ratios may provide some relief if you have kept low PO4 levels or also, low NO3 levels.

    Some plants like more NO3 than 5ppm say.........re read the nitrogen article here..........

    EI will certainly target the N:p ratio you desire, you can test with calibrated kits etc for confirmation.

    There is still no need for test kits.

    The ratio itself is not that critical, having enough NO3 and PO4 is much more the issue. Generally, a lot PO4 takes out glass algae.

    Which is 180 degrees opposite of what many predicted.

    But until you start focusing on the upper ranges, you will not find these things out. Folks in the past have always limited thing.

    EI assumed a max, not a limiting approach.

    If you cannot hit 2-4ppm of PO4 and 14-28ppm of NO3 without a test kit, let me know.

    That's a big range and plants/tank will not use much more than 2-4ppm of NO3 even at very high light, and .2-.6 ppm PO4 per day.

    So dosing once every 2-3 days should maintain that fairly well.
    If you seek more accuracy, you can make solutions of KNO3, KH2PO4 and that will provide greater accuracy for your target range without test kits also.

    We already do that with Trace elements.
    The dosing calculators can tell you precisely what you need to add to say 500mls of water to make a soultion based dosing method.

    Yes, you can maintain a range of 7:1 and go higher than the levels you have set for yourself.

    That's the thing with assuming max levels for a range, it offers much greater flexibility than a specific target.

    Then you do not need the test kits.

    I've tested for a long time, there are reasons why I do not suggest folks as a rule need to test for N:p.

    You can test if you want, but you do not need to tell folks that they need to do it.

    I'm not saying they are worthless, I am saying they are not needed to hit the targets for good growth/low algae.

    If you asked someone prior, and told me the glass algae issue, I would have told you to increase the PO4 dosing(and likely the CO2 if it still persisted), and not a 7:1 ratio.

    Regards,
    Tom Barr
     
  8. Tom Barr

    Tom Barr Founder
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    Re: Astonishing

    Yes. True.

    Also, using liquids will offer you more accuracy if you feel you need it, likely more than a test kit unless you have a very good one.

    10mls of KNO3 solution (2 level tablespoons in 500mls of water) will add about 5-6ppm per dose to a 20 gallon.

    You can do the math a different way also:

    1/4 teaspoon = ~1.67 grams = 10-11ppm of NO3 in an 80 liter(~20 gal) tank.
    12 x 1/4 teaspoons in a a table spoon. 2 x 12 = 24.

    500mls/24= 20.8 mls to add an equivilant 10-11ppm dose of NO3.


    This will increase the stbaility of the dosing amounts more than the 1/4 teaspoon method(but it's a range to target anyway, not so precise!)
    Using an accurate scale to weigh the KNO3 will increase the solution make up accuracy, so you could say 10mls added will increase the ppm by 9.8ppm NO3 etc

    I add a fudge factor of 1ppm for the range due to rock and other stuff in the tank as well as weeklyevaporational losses and refills etc, and also it assumes you have stable CO2 and other non limiting conditions in the tank also.

    If you get an accurate reading for the volume of your tank, you can dail, this in even closer.

    PO4 solutions are already in used with Fleet enemas but you can make a solution for low amounts of PO4 dosing with KH2PO4.

    While accuracy is often discussed and suggested as a reason for test kits.............................................................

    The real question I asked many years ago: how accurate do we need to be to have a nice algae free tank and good growth for all weeds with minimal work and issues with dosing?

    That........is a much better question. As well as the appealing aspects of not testing, associated cost etc.

    You can tweak EI certainly, you can test with it and adjust accordingly to whatever test you want to try.

    But most folks are merely interested in a nice tank and stop testing after they get it.

    Not me though..........

    Regards,
    Tom Barr
     
  9. Tom Barr

    Tom Barr Founder
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    Re: Astonishing

    Based off the observations and the article: do you find any support for this limk that seesm to be way over referenced on the web?

    http://www.xs4all.nl/~buddendo/aquarium/redfield_eng.htm

    I sure don't and it bugs me when sites that discuss this stuff, do not do more careful controls.

    Manys folks have issues keeping tanks and then want to do so called experiments and they cannot even maintain control over the independent variables.

    That leads to poor conclusions and ones that are flatly wrong.
    They mean well, not to dish on anyone, but ............

    You can improve your ability to think, and perform test as well as improve the health of the tank.

    The application of theories to our tanks must be done in the proper context, not Marine algae out in the middle of the ocean and not ratios based on limited systems in nature.

    Many seek to apply limiting methods to deal with algae and grow weeds.
    Without ever exploring the other side, the maximum...............

    They would make poor scientist.
    I teach an enzyme kintetics lab and we look at the min and max pH, substrate concentrations, temps and make graphs of the rates of reaction and also what is the maxmium reaction rate range.

    You can explore the ratios all you'd like, but as long as the CO2 and PO4 are iup and the NO3 is also up, I think the ratio in and of itself is much less important.

    But a 7:1 ratio is not a bad starting point/target as long as ther ranges are up high enough. A Barr Ratio........hehe, I suppose...............

    Regards,
    Tom Barr
     
  10. awrieger

    awrieger Junior Poster

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    Re: Astonishing

    I actually saw that page the day before your newsletter, so I didn't get the chance to try it out as I was planning to!

    I know very little about the Redfield Ratio and how it was developed, but that Dutch person who used it as a base to start experimenting with NO3 levels seems like just a hobbyist like most of us, not a scientist, just tweaking until something works.

    But the Redfield Ratio is similar in a way to the Barr Ratio, isn't it? Too much or too little of one nutrient in relation to the other and you get algae? All about getting balance and that sort of thing. But theirs is 23:1, which is a big difference to 7:1! 23 worked for them, while I've just found 7 works for me. Go figure!

    Speaking of Dutch, another Dutch person, PJAN over at the Planted Tank who you might be familiar with, and who is a plant physiologist, posted this info about 'overpressure'. Having enough of both PO4 and NO3 to push it's way into the plant (osmosis-wise, I guess) as it's being used up by the plant, in an inactive way as opposed to micros which are actively taken up by the plant.

    This sounds simlar to what you're saying as well about having enough available, but I've not seen the word 'overpressure' actually used before this and as the reason for it.
     
  11. Tom Barr

    Tom Barr Founder
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    Re: Astonishing

    Well, rather than over pressure, uptake is driven by concentration, it's less of pressure and more of probability, the chance that a nutrient will come in contact with the enzyme, that's also why heat increases uptake rates, till the heat eventually denatures the uptake enzyme etc............pH has a similar impact around the extremes.

    I would not call it "over pressure" though.........the translation might be part of it though.....

    Regards,
    Tom Barr
     
  12. Tom Barr

    Tom Barr Founder
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    Re: Astonishing

    Thanks for link, I posted some stuff, we will see what he says.

    Not sure if he's piggy backed or is iden[pent of what I've bene saying for nearly a decade.

    I know I've been independent of other folks, then see them verify the findings which give legimatcy to the approach and fosters better overall plant care and direction for the hobby.

    If he is really a plant scientist, then there will be approaches he'll use and input that will be useful.

    Many Dutch and Danish researchers are quite good in the field of aquatic plants, but he might not be active any longer.

    Most of the tropical studies are being done by the Folks in Florida.

    And there is very good reason...........lots of:

    Lakes(7800 of them 4 hectares and over)
    Rivers
    Streams
    Hardwater spring fed CO2 rich waters,
    Many nutrient types

    All subtropical temprature, never freezes, year round growth, Everglades research money availability (Billions$$), a large aquatic plant nursery business present, many good reasons.................

    Dutch and Northern areas do not have such diverse applicable research projects.

    One interesting thing, species richness seems to increase the further north you go in lakes, we can find 6 species of Potamtogeton in northern lakes while only one or two in southern lakes.

    That genus and Podostemacae(the strangest of all aquatic flowering genera) are quite peculiar aquatic plants.

    Regards,
    Tom Barr
     
  13. aquabillpers

    aquabillpers Lifetime Charter Member
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    Re: Astonishing

    Just after I learned about the Redfield ratio and started talking about it, along comes the Barr ratio which changes everything. Sometimes I think that this hobby changes faster than computer technology.

    Please excuse this terribly off-topic reference, but it is kind of funny and somewhat related to Redfield. I was in upstate NY last Saturday and happened upon this place:

    http://www.snowmobilingusa.com/Osceola_Hotel.htm

    It is only a few miles from - - - Redfield!

    Bill
     
  14. Tom Barr

    Tom Barr Founder
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    Re: Astonishing

    Well, I think we are much closer to having most things figured out concerning growing weeds, but....................

    Amount of plant biomass, it's previous health, bacteria estblishment and pruning routines can make a huge difference.

    Those are going to be much more the topics later and on the boards.

    Regards,
    Tom Barr
     
  15. jerime

    jerime Expired Subscriber

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    Re: Astonishing

    Tom, I always read what you're saying about ratio being unimportant and so but usind the redfield idea, i've found out that playing with this ratio (10:1, 7:1 or whatever works) removes the green dots etc'.
    We say ratio doesn't matter but when we change it, we see a difference.

    In that case, it seems to me that ratio does have significant role in it.
    Can it be because of PO4+NO3's role in amino acids and other plant structures?

    Thanks.
     
  16. Tom Barr

    Tom Barr Founder
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    Re: Astonishing

    The ratio itself is not a secondary thing, for example I can have 40ppm of NO3 or 15ppm and still have no GSA algae on the glass, with 2-3ppm of PO4 that is stable.

    When we drop the PO4, then issues seem to occur, but this is not due to a ratio.

    Do you see the difference between the two statements where one says it's important and the other says it's not?
    The above example shopws that the ratio itself is not the issue, rather, having enough of the nutrients is.

    You can have a 7:1 ratio, say 0.7ppm NO3 and 0.1ppm PO4(not taking into account the Oxygens) and have lots of green spot algae.
    Maintaining a stable level at high light/CO2 is also impossible.

    But it still shows that you cannot broadly say the ratio is the key.

    If the plants have enough, that is the key and they can have a lot more excess than previously thought and still do quite well.

    That upper range allows us a wide range of dosing ratios and habits etc.

    It's a good thing also. Makes dosing easier.

    The ratio 's role may be more useful in testing and estimating the N:p balance as both drive the other in larger ways like adding CO2 drives more N and P uptake also.







    Regards,
    Tom Barr
     

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