Redfield ratio

jtparsons

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Jan 18, 2009
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Free of algae with Redfield Ratio | Aquariumpagina's van Charles Buddendorf

Here's the link I was talking about in my noobie post. Redfield's experiences with algea and the ratio between nitrate and phosphate levels. Looks like with the EI method you could be anywhere from 1/5 thru 1/10. Redfields #'s are a little different. Think there's anything to this info?

Anyways my tank is no longer cheap DIY:) . Purchased c02 tank, cellaniod, good needle valve, bubble counter, ADA drop checker(I was mesmerized into credit card submission by the pretty blown glass), Koralia power head, glass diffuser$$$$$$$$$$$$:eek:

EI questions.
1. Is all the Potassium comming from the KN03? Do I need to add more K.
2. Durring the weekly water change do you dose back the N03 and P04 for the volume of water being changed 50% or full dose?
3. How does 8GH and 4KH sound? I want to do the 4 to 1 ratio EI describes but that makes my Gh really high or my Kh really low?

Thats all and thanks again. You should all be ashamed of yourself for bankrupting young aquarists around the world with your "high tech" advice. I will be posting reciepts for riembursment. J/K:D
 

tedr108

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Re: your EI questions...

1. You also get potassium from KH2PO4 (potassium phosphate).

2. EI is flexible on dosing. However, if you read up on the EI threads in the Articles forum, the guidelines are to dose the macro nutrients 4 times per week and micro nutrients 3 times per week. I usually did my macro dose on the day of the water change. In other words, I didn't up my dosing on water change day.

3. 8GH and 4KH water hardnesses sound fine, no need to mess with it. I'm not sure what ratio you are talking about, unless it is the 4 to 1 ratio of KNO3 to KH2PO4, which has nothing to do with water hardness.

Hope this helps.
 

jtparsons

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Jan 18, 2009
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Have hard water?

Great, you do not have to add any baking soda and GH builder to your tank. Adding enough GH to bring the levels to 3-5 GH degrees will address higher light tank needs over a week's time. You can use SeaChem Equilibrium for this or a mix of CaCl2 (or CaSO4 although it is not as easy to dissolve into water) and MgSO4 at a 4:1 ratio to increase GH. You can add this without knowing what your GH is by adding 1 degree's worth after a weekly water change (or slightly less with less frequent water changes)

This qoute from "The estimative Index of dosing, or no need for test kits.
I guess my question makes more sense this way. Are these parmeters correct and okay?
Tap water is 1DGH and 1DKH
If I dose 4DGH/DKH worth of Calcium I will have 5DGH/5DKH
Then I could dose 1DGH worth of Magnesium 6DGH/5DKH

I understand the dosing schedule this way. Every other day macro's. Traces on the off days. What I dont understand is when I do the weekly water change "reset" and redose the macros during the water change do I use a full dose for a 15gal aqaurium or 7.5 gallons for the volume of the water change.

Thanks -Jon
 

neil1973

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Dec 17, 2005
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Here's the link I was talking about in my noobie post. Redfield's experiences with algea and the ratio between nitrate and phosphate levels. Looks like with the EI method you could be anywhere from 1/5 thru 1/10. Redfields #'s are a little different. Think there's anything to this info? said:
I think there is a lot of confusion about the Redfield ratio. It is essentially a ratio of C:N:p in deep ocean waters (a very stable environment) that often corresponds well to the ratio of these elements found in marine phytoplankton. This has nothing to do with freshwater systems and higher plants. Another area of confusion among proponents of the redfield ratio in planted aquariums is that it is an atomic ratio i.e. 16 atoms of N to 1 atom of P. It is then often suggested that this ratio should be followed in terms of nitrate and phosphate. When adding nitrates and phosphates to aquariums we are normally talking about mass ratios which would roughly be 7:1 for N a P and 10:1 for N03 and PO4. Again this is almost certainly irrelevant for freshwater plants but does serve to highlight the confusion.

cheers
Neil
 

Tom Barr

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Jan 23, 2005
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neil1973;33054 said:
Here's the link I was talking about in my noobie post. Redfield's experiences with algea and the ratio between nitrate and phosphate levels. Looks like with the EI method you could be anywhere from 1/5 thru 1/10. Redfields #'s are a little different. Think there's anything to this info? said:
I think there is a lot of confusion about the Redfield ratio. It is essentially a ratio of C:N:p in deep ocean waters (a very stable environment) that often corresponds well to the ratio of these elements found in marine phytoplankton. This has nothing to do with freshwater systems and higher plants. Another area of confusion among proponents of the redfield ratio in planted aquariums is that it is an atomic ratio i.e. 16 atoms of N to 1 atom of P. It is then often suggested that this ratio should be followed in terms of nitrate and phosphate. When adding nitrates and phosphates to aquariums we are normally talking about mass ratios which would roughly be 7:1 for N a P and 10:1 for N03 and PO4. Again this is almost certainly irrelevant for freshwater plants but does serve to highlight the confusion.

cheers
Neil

Could not have said it better myself.

I let Charles know about the error between mass and atomic ratios, he's never changed it, what can you do other than that?:rolleyes:

If I made a mistake like that, I'd change it asap so more folks would not know:p

Regards,
Tom Barr
 

tedr108

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Nov 21, 2007
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I guess my question makes more sense this way. Are these parmeters correct and okay?
Tap water is 1DGH and 1DKH
If I dose 4DGH/DKH worth of Calcium I will have 5DGH/5DKH
Then I could dose 1DGH worth of Magnesium 6DGH/5DKH

I understand the dosing schedule this way. Every other day macro's. Traces on the off days. What I dont understand is when I do the weekly water change "reset" and redose the macros during the water change do I use a full dose for a 15gal aqaurium or 7.5 gallons for the volume of the water change.

Jon,

From what you are writing, I feel like you are confusing macros with GH builders. As far as EI macro nutrients (KH2PO4 & KNO3 normally), you do not typically change the dose on a water change day. Now, if you are talking about raising your GH by whatever method you choose ("resetting" the water), then, yes, you would only use enough GH builder to raise the GH of the water being replaced (7.5G in your case).