# is PMDD+PO4 a method?



## jarthel (2 Dec 2009)

I've seen EI and PMDD+PO4 from theplantedtank.co.uk. I've also read EI from this forum. But I'm not really sure PMDD+PO4 is a method along the lines of EI. Because it seems it's more like a fert solution more than anything else. James does say to dose the tank everyday so it's like a method. BUT in saying that, other solutions could have that in its instructions.

I found this from the seachem flourish product page:
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Use 1 capful (5 mL) for each 250 L (60 gallons*) once or twice a week. For smaller doses, please note that each cap thread is approximately 1 mL. Refrigeration after opening is recommended but not required.
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So you could somewhat say that it's a method (i.e. Seachem flourish method) as well.

Can someone please enlightened me?

thank you very much

ps. I search the forum but can't find relevant info on the PMDD+PO4 method.


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## JamesC (2 Dec 2009)

Not sure what you are trying to ask. EI is based on a a set of chemicals that are added to a tank at set amounts. PMDD is the same. Both can be modified to suit your particular needs.

James


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## jarthel (2 Dec 2009)

JamesC said:
			
		

> Not sure what you are trying to ask. EI is based on a a set of chemicals that are added to a tank at set amounts. PMDD is the same. Both can be modified to suit your particular needs.
> 
> James


But EI is not just a solution I think. there are other procedures involved like massive water changes. So in a sense it's a method. But in PMDD is just a solution much like other ready made solutions out there. how did PMDD become a method? 

I asked since it's been mentioned several times (even mods have mentioned it) that PMDD+PO4 is a method.

that's all


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## plantbrain (2 Dec 2009)

jarthel said:
			
		

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EI is more a concept, you can use the concept to make management easier.
Likewise, PMDD is a concept as well, and you can use the notion of limiting PO4 to make management easier(relative of what was done prior to PMDD, pre 1994/1995).

PMDD+PO4 is what I suggested back about 1995-1996.

See here:

http://www.barrreport.com/showthread.php?t=2386

As far as a conceptual basis of a method, it suggested that there was no limiting factors for algae and the nutrients did not control the algae blooms.

Some methods suggest this however, which is incorrect to say as it's easy to falsify. We can say this however: it(limiting say PO4) can make management of CO2 easier for folks who cannot manage CO2, but does not address the root issue(CO2). It's an indirect management approach.

All nutrient dosing is rate based. So CO2(or not), and light intensity must be factored in as well since they govern plant growth rates more than nutrients alone.

PPS and PMDD + PO4 are essentially the same method, one is a bit richer and the other is a bit leaner.
But whether I add 2 pumps or 4 mls of this liquid vs 1 pump or 2 mls of that is not a method difference.
Or if I add 60 grams of KNO3 and 10 Grams of KH2PO4 vs 3 grams of KH2PO4 to stock solution. 

They all get modified to some degree, and most all methods all add N, P, K and traces in some form or another at some rate.

So what matters is really are the* rates *of growth/dosing within context of light and CO2.
Then you can compare things.

Sediment locations could be called a method I'd say also.
But they can be used with PMDD+PO4 or EI or Tropica or brand name stuff as well.


I'm not too sure what we might call or not...... a method.
I do not think it matters a whole lot. If you do, please explain why you think this and we can go from there.
That would be more helpful.

PMDD is more a daily routine, EI has been taken to be more a 2-3x a week routine.
But either can be done with the other's frequency if desired, and at similar target concentrations.

I think those are more human habit issues.
If you feed fish daily, then dosing daily might be best for you.
Either way, whatever gets you to be consistent is the key.

Regards, 
Tom Barr


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## jarthel (2 Dec 2009)

plantbrain said:
			
		

> jarthel said:
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Thanks Tom for the reply. It doesn't really matter as long as the plants are happy. I was just curious. that's all 

Thanks for the detailed explain. I appreciate it very much


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## plantbrain (3 Dec 2009)

Well, it's a basic obvious question, but not one with any clear answer I could reason through personally.
Often those are good questions to explore  

Regards, 
Tom Barr


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