# Confuse about the PPS- Pro method vs estimate index



## drunkenmastera (Oct 21, 2009)

This is my first time dosing dry fertilizers. I am a little confuse by what I have been reading.

I read about estimate index dosing. You dose straight in or mix with water. 

The PPS-Pro, you mix it all in a bottle and dosing according to tank size.

Isn't both of these methods the same, but the EI has recommendations for 50% weekly water changes. However, the PPS-Pro can have water change or no water change.

I know there is a fine line if you have heavy fish bioload. Can anyone clarify this for me please?


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## wet (Nov 24, 2008)

Imagine for a moment that we add 10ppm Stuff into a tank every week, and that tank has so many plants it uptakes 8ppm Stuff per week.

If we did no water changes for 3 months, Stuff would look like the green line here.


If we did 50% water changes every week for 3 months, Stuff would look like the green line here.


PPS-Pro, the first example, says we should attempt to maintain that target of 10ppm. Under its rules, you would also measure the tank using calibrated kits and adjust dosing once you passed 10ppm. Otherwise, you could get closer to the red line than the green line. (If following PPS-Pro strictly, you'd probably adjust the Stuff mixture or dosing frequency around week 3/day 20 to maintain the 10ppm Stuff.)

EI says theses things do not matter if we export (water change) to bring the tank back to baseline. So, even if we're unsure about that 8ppm uptake, or if we're really dosing 10ppm, we've a built-in safety that will stop us from messing up.



> Isn't both of these methods the same...


Yes! The idea is we feed our plants. ppm and such is unimportant. Both PPS-Pro and EI stabilize with their built-in mechanisms (testing and waterchanges, respectively). The particulars and specifics of each method can easily overlap with one another. Both methods have lots of leeway in the particulars.



> I know there is a fine line if you have heavy fish bioload. Can anyone clarify this for me please?


This is less true with more plant mass, and note each of these methods suggest very high plant mass. If you fear extremes, you use the built in mechanisms above or adjust the dosage downward.

They're guidelines that have much more in common than many acknowledge. As you research, note the common ground -- feed your plants, do it in a somewhat stable manner, have good CO2, grow lots of plants, and pay attention to what your plants and fish tell you -- and you'll do great. If you'd like to use either method as a strict blueprint, that works too: pick the method that fits your lifestyle, then try to remember plants aren't that smart and all this stuff are a guidelines, not anything strict.


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## DVS (Nov 20, 2005)

> As you research, note the common ground -- feed your plants, do it in a somewhat stable manner, have good CO2, grow lots of plants, and pay attention to what your plants and fish tell you


I couldn't agree more with this statement and I'm constantly surprised by the number of people who seem to miss it. Every successful method relies on this, (though el naturel uses carbon (soil) instead of CO2). One refinement of the statement might be an appropriate amount of light for the sources of carbon and ferts.

The real difference as Wet noticed was the method that is used to deal with potential excess nutrients. PPS uses testing to tailor your dosing so nutrients stay within the "acceptable" range, EI uses water changes. Unless there is a specific reason water changes need to be avoided, I believe EI is the more robust system.


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## drunkenmastera (Oct 21, 2009)

thanks for the clarification. I guess there is no strict guidelines, it depends on many scenarios.


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## bsmith (Dec 13, 2006)

drunkenmastera said:


> thanks for the clarification. I guess there is no strict guidelines, it depends on many scenarios.


You are correct. I'm not as familiar with pps as I am with ei but again with the ei method you just dose all nutrients in excess so you know there are no limiting factors you are missing and then use the weekly 50% wc to reset the chemistry. In my case since i have been doing it for so long I have my ei dosing amounts pretty fine tuned so there are not huge excess levels of any one nutrient. This is the best way to dose IMO and after you find the sweet spot for amounts to be dosed you are good to go.


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