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Re: Redfield ratio and Algae control

PostPosted: Sat Dec 13, 2008 11:03 pm
by freshfish
LOL Dutchman has been under the weather and not able to be around for a bit, he's going to be tickled pink (and perhaps somewhat insufferable :whistle: JK!!!!) when he gets back and hears how well it's working out for you! :thumb:

Re: Redfield ratio and Algae control

PostPosted: Sun Dec 14, 2008 5:36 am
by mralgae
LOL thanks FF for letting me know, i was hoping he would be around to try and shed some light on the figures for RR. hope he is not suffering as i was and has a speedy recovery. :yippee:

give my regards if you do speak to him :)

Re: Redfield ratio and Algae control

PostPosted: Sun Jan 04, 2009 3:00 am
by Dutchman
mralgae wrote: . . .I am not scientifically astute so I have to rely on others for the analysis side of things. While talking about this on other forums I have had it pointed out to me that the ratio is wrong.

RR is an atomic ratio based on the no# of ATOMS, not mass.

So the mass conversion must include the moles/gram.
P is 30.97 g/mol
N is 14 g/mol.

This means the mass ratio is 7.2 N : 1P

For NO3 and PO4, then you would use about 10:1.
:scratch: But that is correct Image There is no disagreement here from my side. Please check it out:
The optimum RRatio is 16 N-gmol/P-gmol. The mass-ratio is therefore 10-gr NO3/1 gr PO4.

BTW: Thanks for the well wishes. I"m improving very quickly. So, no complaints from me, :D

Regards
Cor

Re: Redfield ratio and Algae control

PostPosted: Sun Jan 04, 2009 8:08 pm
by mralgae
OOooook I don’t care if this makes me look silly or not, but as said I am thick when it comes to chemistry. I should have paid more attention in school…… :(

Let me see if I got this right?
RR = atoms
BR = mass

And converting the atoms to mass they both work out to be the same, except one is atoms & one is mass?

i know only to well what its like not being well And glad to hear your on the mend…. :waahooo:

Re: Redfield ratio and Algae control

PostPosted: Sat Feb 07, 2009 9:45 pm
by mralgae
Amazing how people can ignore the facts for them selves and put it down to some thing other that the facts. As I have said previously using the RR in this way is the first time EVER I have been able to use ANY ferts with out an outbreak of algae. Although I did completely mess things up and had to do a BO to reset the tank but this was my fault.

As I have also said before I have been putting the RR about on other forums and along with one of my co-owners of one we have had great success with it. While others have & continue to do is poor water on the fire even before they have tried it. Then others who have tried the RR have also had great success with it as we have had. Again being able to use ferts where they have not been able to do so before.
I think that an article that has been spoken about either revamp or reproduce the old article in some way would most definitely be worth every effort to allow folks to make up their own minds on this.

Thanks to Dutchman (mad scientist) for bring this to the for-front where it needed to be.
:clapping:

Re: Redfield ratio and Algae control

PostPosted: Wed Nov 18, 2009 2:58 pm
by Hurriken
So if I kept my RR at 16 like you said algae should stay in check but will I also have optimum growth of my plants? It seems like there are so many factors to consider with a planted tank. What about the effects of CO2, light, and plant species?

Re: Redfield ratio and Algae control

PostPosted: Thu Nov 19, 2009 12:01 am
by Dutchman
As long as the RR is maintained at 16, you can still vary the absolute quantities, ie: you can maintain 10ppm NO3 and 1ppm PO4, or 25pmm NO3 and 2.5ppm PO4. The plants will grow in response, although at 25ppm NO3 you may need to look at the intensity of your lights, AND consider CO2 injection.

Cor

Re: Redfield ratio and Algae control

PostPosted: Thu Nov 19, 2009 1:37 am
by Hurriken
So will CO2 or lights effect the variable? For example lets say with the current regimen the RR is 16 stable. So then we change from....off the top of my head....Java Fern to a Pogostemon Helferi as something that needs more light. Then we jump the tank from 1.5 watts per gallon to 6 watts per gallon and add CO2. With the same dosing routine will the RR stay the same or change?

Re: Redfield ratio and Algae control

PostPosted: Thu Nov 19, 2009 1:46 am
by Dutchman
I'm not too sure about that Ken. I think the RR will be maintained, but what exactly will happen under those conditions is probably anyone's gues.
If you read the abstracts, then its realy all about statistical averages, saying:"somewhere in the middle lies a range that's least affected by algae." I'm sticking to it, and sofar . . . no algae.

Re: Redfield ratio and Algae control

PostPosted: Thu Nov 19, 2009 7:10 pm
by freshfish
Your dosing will have to change depending on plant growth/absorption. IDK that a rosette plant would have as much impact, but probably some fast-growing stems would.

Re: Redfield ratio and Algae control

PostPosted: Thu Nov 19, 2009 11:03 pm
by Dutchman
Hurriken wrote:So then we change from....off the top of my head....Java Fern to a Pogostemon Helferi as something that needs more light. Then we jump the tank from 1.5 watts per gallon to 6 watts per gallon and add CO2. With the same dosing routine will the RR stay the same or change?
I think I misunderstood.
The RR must stay the same(ie:16), but the dosing must increase in line with the new nutrient demand.

Re: Redfield ratio and Algae control

PostPosted: Thu Nov 19, 2009 11:39 pm
by Hurriken
Now it makes sense. Thanks.

Re: Redfield ratio and Algae control

PostPosted: Sun Nov 29, 2009 10:19 am
by Wolfenrook
That's where testing comes in handy, even accounting for the alleged inaccuracy of some kits they do serve to give a warning if changes in uptake occur (by the way, the full RR actually includes carbon in it, so this remains an important factor, just one that is easier to manage as I have yet too hear of anybody having algae problems because of too much carbon). As an example, when replacing old tubes nitrate and phosphate uptake often increases due to the increase in intensity, often not in the same ratio either, meaning you can end up with your nitrate been a little too low to maintain RR, whilst phosphate doesn't reduce as much (I have found that different plants actually have different rates of uptake for each, for example IME HC Cuba uses a lot more phosphate).

The only time I have had algae probs using RR to monitor my dosing have been where I have gotten lazy and not done enough testing, instead sitting on my laurels and relying on my established dosing quantities. Oh and it's much easier to work with the buddy ratio of 10:1 for nitrate:phosphate rather than actual RR which is for Nitrogen:Phosphorous:Carbon, with the buddy ratio the molarities etc have already been taken into account so there is less maths to do. Always a good thing in my book.

Ade

PS. I'm the co-owner MrAlgae mentioned. lol

Re: Redfield ratio and Algae control

PostPosted: Wed May 27, 2015 6:28 am
by Scheccia
Hi @Dutchman,
I'm in a group that develops an application for android, its name is Aquarium Manager. Now we add the redfield ratio and we read your topic, the developer ask if you can help us.
Thanks.

Re: Redfield ratio and Algae control

PostPosted: Wed May 27, 2015 6:34 am
by Scheccia
Hi Dutchman, excuse me if i write here...
I'm in a group that develops an application for android, its name is Aquarium Manager. Now we add the redfield ratio and we read your topic, the developer ask if you can help us.
Thanks.