# Poor Man's Pfertz Dosing (PMPD)



## Philosophos (Mar 1, 2009)

This thread is to be part of an ongoing series here at APC, with the original thread and series posting started over at The Barr Report

Poor Man's Pfertz Dosing (PMPD)
By Dan Enright​
*Preface:*

This piece of writing is intended as an interactive thread as much as it is an article. It is intended to be an examination of the pfertz line from top to bottom, with an emphasis on accurate reproduction and the cost of nutrients. I intend to update it for accuracy, correct any technical issues as they arise, and partake in any dialogue on the subject. I hope this to be the first of a series of discussions deconstructing various fertilizer brands, and their implications within the planted tank.

As a brief disclaimer of sorts, I can definitely say that this is all being written for the DIY inclined. Whether pfertz, ADA, Seachem, etc. every company understands that there will be those, both hobbyist and competitor, looking to deconstruct and recreate their products themselves. Their products are for those who do not feel comfortable or are otherwise not inclined to mix their own fertilizers. I encourage those who do not feel that they can work responsibly with any of the compounds mentioned within this article to continue buying premixed fertilizers.

*The Short Version:*

This section is for anyone who wants Pfertz fast, no questions asked. What follows after is the longer explanation that allows for some of the technical details. Any of these numbers can be halved, quartered, doubled etc. to meet your needs.

The ingredients for each bottle are listed below; simply add the listed weight to half the volume of distilled deionized water, then top off to 1L and stir. It may take some time stirring (or some gentle heat; warm not boiling) to get things right. For pfertz [N] it may be advisable to get the urea and potassium nitrate as a solution in separate volumes of water, then combine and top off.

*Pfertz [N]:*
KNO3 (Potassium Nitrate): 61.27523782g/L
CH4N2O (Urea): 19.3193426g/L

*Pfertz [P]*
KH2PO4: 19.17446678g/L

*Pfertz [K]*
K2SO4: 43.97633951g/L

Pfertz [M] is not covered here as it is far more difficult to reproduce. The reasons for this are covered later on.

*On Pfertz and its Content Labeling:*

Pfertz outlines its nutrient concentrations as a guaranteed analysis. By law these numbers have to be accurate. The derivatives for each of these nutrients are not required listing as far as I have been able to determine. At a glance, the analysis does not contradict the ingredients listed. This lack of contradiction does not negate the possible use of other compounds to achieve the same guaranteed analysis. I suspect as discussion develops, better insight as to regulations and labeling will surface.

At this time, everything I am writing is based on the assertions pfertz makes about its own product, from its own site. In the future there may be some sort of analysis done, but for now the scope is restricted to statements made by the company. None of what I am posting is more than information derived from what pfertz has been required, or chosen, to release about its own products.

The math behind this project was very interesting. I started with the presumption that all measurements had been given with correction for specific gravity. It turns out that the pfertz site did not make this consideration, and simply calculated the presence of their nutrients as if everything being added was the same density as water. Other deviations from the possibility of actually achieving the analysis given with the listed compounds are noted in the respective sections. For any of my own calculations, I am more than happy to share them. I would include all of them here, but it would result in an article several times this length.

*Macro Analysis:*

I am starting here with the macronutrient analysis for the [N] [P] and [K] bottles. These will be the products most easily examined and reproduced. Mixing comparable micronutrients is a task far more difficult and expensive, one being on the scale of more commercial than private aspirations. This being an article for the hobbyist, I will leave micros as a topic of brand comparison and dosing.

It should also be noted that there was incongruence between the listed K+ on the site and the K+ that is forcibly added through the above levels. This issue with K+ shows up in every product involving potassium as its base, aside from pfertz [K]. These contradictions sometimes blatantly violate what is possible given the atomic weight of the compounds listed. As such, the topic of K+ is a bit hit and miss. It should not effect any other outcomes outside of the KNO3:urea ratio in pfertz [N], however it does leave a good number of questions unanswered. Hopefully some of it can be answered in the following thread discussion.

For all of the information on the contents of pfertz, the ingredient labels can be found at: http://www.pfertz.com/analysis.html

*Pfertz [N]:*

Pfertz [N] has a label for its product listed as follows:

_Nitrogen [n] (500 mL and refills): 1.75 - 0 - 5.0

Total Nitrogen (N): 1.75%
Available Phosphate (P2O5): 0.00%
Soluble Potash (K2O): 5.00%

Derived from: Potassium Nitrate, Urea_

While the nitrogen is most accurately given as N, by the time the product is broken down, a more accurate and hobbyist friendly analysis would be:

*Total Nitrogen:* 1.75%
*(N) KNO3: *0.848899026%
*(N) CH4N2O:* 0.901100974%
*Total N Expressed As NO3:* 7.746907734
*PO4:* 0.00%
*K:* 4.150563694%

From the above, these numbers were derived as concentrations for:

*KNO3 (Potassium Nitrate):* 41.50563694g/L
*CH4N2O (Urea):* 19.3193426g/L

Mixing up a batch of your own may be a little tricky on this one. I am not sure as to the compatibility of KNO3 and urea in stock solutions. A good method would be to dissolve both thoroughly in separate measures of DI H2O, and then combine them. Hearing from someone with urea around that can test the stability of this compound would be helpful. Alternatively, the same dosing level of N can be reached through a weight of 126.3185171g/L KNO3.

*Pfertz [P]*

The phosphate portion of pfertz dosing was significantly easier to figure out than the [N] product. While the derived K+ from necessary KH2PO4 was off according to both my own and APC's Fertilator calculations, it will not effect the conclusions I have reached about the required KH2PO4.

The given analysis on the pfertz site for this product is:

_Phosphorus [p] (500 mL and refills) 0 - 0.35 - 0.25

Total Nitrogen (N): 0.00%
Available Phosphate (P2O5): 0.35%
Soluble Potash (K2O): 0.25%

Derived from: Monopotassium Phosphate_

In a more helpful format, it would be listed as:

*Total Nitrogen (N):* 0.00%
*PO4:* 1.338147875%
*K+:* 0.207528185%

The necessary KH2PO4 to achieve the given level of PO4 would be 19.17446678g/L. Mixing this product would be as simple as adding the compound to a little DI H2O and topping off to 1L. Naturally this level can be adjusted for batch sizes and rounded as scale accuracy permits.

*Pfertz [K]:*

This product was by far the easiest to work with of the pfertz line. Plain K2SO4, and a K2O listing of 5.1% (4.233752% K+) made it all straight forward. After dealing with the last two, it really made me wonder whether the K+ was listed correctly, but the given information is all we have to work with. The necessary level of K2SO4 works out to 
42.337523/L, and mixing it can be done precisely the same way as mentioned in the phosphate section.

*Macro Dosing:*

So what sort of nutrients does this mean for your tank? The pfertz site doesn't really tell you what sort of nutrient levels are achieved through their method of dosing. Their analysis also leaves confusion as to what levels of K+ are achieved. As such, both implied levels (DIY and true pfertz) of potassium will be shown, as well as the rest of the results of dosing the pfertz line.

Given the instructions for the product, we will be looking at a high tech dosing routine at 7x a week, 1 pump per 10 gallons per product at 1.2ml/pump. The extra pump per day will be presumed to be as part of the 7 day a week schedule as the 7th day, allowing for a 6 day dosing plan with the typical resting day before water change.

In accordance with the above schedule, and nutrients based off both the site and my own calculations:

*NO3:* 17.19074ppm
*PO4:* 2.969411ppm
*Pfertz Line K+:* 17.63336ppm
*PMPD K+:* 16.34168352ppm

So despite some small deviations in K+ and N source ratios, the PMPD macro solutions should be very reasonably close to the brand version.

Nutrient-wise, these levels of dosing aren't too bad. These levels are comparable to a lot of current dosing recommendations, and are not likely to become limiting too quickly. Pfertz macronutrients have shown to work in a number of planted tanks, and the nutrients reflect as such.

*Micros:*

I've put micros on their own for the reasons mentioned earlier. There will be no breakdown on how to mix up a batch of micros, since it would require making about 100 bottles with a rather expensive scale to get any accuracy. Besides that, the issue of keeping 100 bottles stable for the years it would take a hobbyist to dose this solution is something that inclines me to purely deal with the result of dosing their product within the column. The site lists elemental properties in a convenient form; as such I will keep this section to pure dosing results. Here are those numbers, presuming the same dosing routine as in the macro section:

*B:* 0.011317131ppm
*Co:* 0.000443809ppm
*Cu: *0.000110952ppm
*Fe:* 0.119828443ppm
*Mn:* 0.015089508ppm
*Mo:* 0.001775236ppm
*Ni:* 0.000110952ppm
*S: *0.009541895ppm
*Zn:* 0.00097638ppm

While micronutrients aren't my specialty, nothing here seems too far out of line. The iron could be higher, but it's definitely not insufficient. I think the cost analysis up next will be a bit more telling in terms of criticism.

*Pfertz and Cost:*

The current running price for a complete refill of pfertz ([N], [P], [K], [M]) runs $107.99 right now. On their own, each of these jugs are priced evenly, so this cost can be evenly divided for the NPK line. One jug being about 1892ml, the cost is effectively $14.27/L.

By comparison, one can pick up the same quantity of compounds for 1L each of N, P and K of PMPD for about $0.975 plus $0.280 if you want the equivalent sort of micro dosing from CSM+B, and something like $0.210 for DI H2O. End cost is about $1.47/L ; a hair more than 1/10th the price. Add the fact that you're not paying to ship water weight, and you'll be saving even more.

If you want something other than CSM+B for micros, Seachem's Flourish is a comparable price at $27/2L, usually around $30-$35 in stores, but without the cost of shipping. Flourish also tends to show higher nutrient concentrations: http://www.aquarticles.com/articles/plants/Podio_Fertilizer_Comparison_Chart.html

All pure cost criticisms aside, Pfertz doesn't do too bad in bulk considering costs. Having mixed my own stock solutions, and knowing the time it takes, the markup isn't completely unreasonable. Packaging probably runs around $5 each for the big ½ gal jugs, total nutrients and water we'll say $1 given their bulk volume, leaving somewhere around $10/unit for covering the rest of costs and wages.

The small bottles, on the other hand, don't seem to be worth the price. Costs there are about $27/L and you can bet a good chunk of it is in the fancy little bottles. For those prices, it's probably worth it to measure the stuff out, or alternatively find cheaper pump bottles and buy bulk off the start.

*What Now?*

Examine, discuss, rant, plan ahead. This is to be the first of a few large posts and articles examining various brands of fertilizers, the nutrient parameters they achieve, and their costs. At the end I'd like to culminate everything with a comparison of multiple brands. I'd like to see this one discussed for a while, corrections made, and the pfertz line figured out a little better. Once things quiet down and I feel like doing this all over again, I will work on the next post. If you would like to reproduce this article somewhere, let me know and I will edit it into something that looks more like a stand-alone piece.


----------



## davemonkey (Mar 29, 2008)

Philosophos, thanks for posting this!! It's a very informative read, and I actually think I'll give the K and P a try since I have some extra Potassium sulfate on hand as well as Monopotassium phosphate. Except I'm going to try for a smaller batch.

By the way, is there a fair approximation of how many grams per teaspoon (or 1/4 tsp) for KH2PO4 and K2SO4?

-Dave


----------



## Philosophos (Mar 1, 2009)

davemonkey said:


> By the way, is there a fair approximation of how many grams per teaspoon (or 1/4 tsp) for KH2PO4 and K2SO4?
> 
> -Dave


I find with tsp's you're going to get a large margin of error; you can expect +/-5% even once you've trained yourself with a scale. That being said, if you don't mind dosing a little loose then here's fertilator's conversion factors as of a couple months back:

Nitrate NO3:
KNO3: 5.2g/tsp
Ca(NO3)2.4(H2O): 4.8g/tsp

Phosphate PO4:
KH2PO4: 5.6g/tsp
K2HPO4: 4.5g/tsp
NaH2PO4: 4.5g/tsp
Na2HPO4: 4.5g/tsp

Potassium K:
K2SO4: 6.4g/tsp
KH2PO4: 5.6g/tsp
K2HPO4: 4.5g/tsp
K2CO3: 4.5g/tsp
KCl: 4.5g/tsp
Seachem Equilibrium: 5.33g/tsp

Calcium Ca: 
CaCO3: 1.2g/tsp
CaCl2: 4.4g/tsp
CaCl2.2H2O: 3.6g/tsp
CaCl2.6H2O: 4.5g/tsp
CaMg(CO3)2: 5.2g/tsp
Ca(NO3)2.4(H2O): 4.8g/tsp
CaSO4.2H2O: 3.1g/tsp
Seachem Equilibrium: 5.33g/tsp

Magnesium Mg:
MgSo4.7H2O: 5.1g/tsp
MgCO3: 4.5g/tsp
Miller Microplex: 3.9g/tsp
CaMg(CO3)2: 5.2g/tsp
Seachem Equilibrium: 5.33g/tsp

Iron Fe:
CSM+B: 4.3g/tsp
Miller Microplex: 3.9g/tsp
Seachem Equilibrium: 5.33g/tsp
10% DPTA: 4.4g/tsp

Some of that has changed a little I think, but not 100% sure. Those factors are also based on averaging out from a pile of different people's estimates.

Ask for a scale for Christmas this year; it'll let you do all sorts of more interesting things for about $20. You'll never have to pay for 4kh solution and you can calibrate all your test kits


----------



## moogoo (Mar 19, 2009)

um.. It takes me about 5-10 mins to mix my solutions and costs me $0 cause i reuse bottles. 



cost of dry ferts is about $20 for all i need and lasts me about 2 years if not more for my 42 gal and 10 gal tanks. 

if you want to save money and do it right, do it yourself  that's what the fertilator's for


----------



## bgzbgz (Jul 6, 2007)

I don't see what the big deal is. Why the long rant about pfertz.

Just figure out how much ferts it would take to add 4ppm no3 and 1ppm po4 to your tank.
Multiply those weights by 20. Add to 200ml distilled water, dose 20ml every other day. Done.

This is EI in liquid form, and it only took a few sentences. 
What more do you need.


----------



## Philosophos (Mar 1, 2009)

Well I just wouldn't ever imagine ever seeing you two here 

Moogoo, using fertilator should be for double checking your information. I don't think anyone should rely on it 100%, and it even says so right beside the thing. Some people start from pfertz but they don't want to pay 10x what they could pay, and they're willing to do the work. They can't do the math up front, but they may learn in the future. Knowing that there are those who would be willing to pick apart the work I've done (would you like to?  ) I've left some of the article with insights to my process for doing all of this that answers some of the basics.

BGZ, it's not a rant about pfertz; it's just looking at what we can figure out. Knowing what it is will show us why it works, and there are people who swear by pfertz. It's the same thing (to a lesser extent) as pulling an analysis on ADA fertilizers to know what they consist of in order to understand the ADA system better. I learned things tinkering with this brand; I suspected leaner dosing at first, and an analysis that would've been SG corrected. It turned out that wasn't the case. Being that I spent the time to poke at it all, doing a write up on what I found wasn't that big a deal by comparison.

Oh, you'll also find standard EI sits at higher PPM's, especially for the PO4 which is more like 11ppm or so. Doing macros in at the same time as the micros and some of the stability issues with the PO4 is also something I wanted to get into.


----------



## Bert H (Mar 2, 2004)

Nice breakdown, Dan. So if I understand your analysis correctly, what they actually recommend on the dosage works out to roughly 17ppm NO3 and 3ppm PO4?


----------



## Philosophos (Mar 1, 2009)

Ya, about there. Of course the "high tech" label dosing is what I went off of. I suppose it wouldn't hurt to post what 1 pump is equal to in ppm for a start:

*1 pump N:*
Total NO3:	2.455819821
Total PO4:	0
Total K:	0.871653328

*1 pump P:*
Total NO3:	0
Total PO4:	0.353501271
Total K:	0.025554445

*1 pump K:*
Total NO3:	0
Total PO4:	0
Total K:	1.616732962

Based off of that, here's what the various dosing instructions found here will result in:

*"The Simple Solution"*
_ Dose nitrogen [n] 2x per week @ 1 pump per 10 gallons._
Total NO3:	4.911639642
Total PO4:	0
Total K:	1.743306656

*"The Medium-Tech Solution"*
_Dose nitrogen [n] and [m] 2-4 times per week @ 1 pump per 10 gallons._
Same as above for 2x, 4x would be:
Total NO3:	9.823279285
Total PO4:	0
Total K:	3.486613312

*"The High-Tech Solution"*
_Dose all liquid fertilizers 5-7 times per week @ 1 pump per 10 gallons._
5x a week:
Total NO3:	12.27909911
Total PO4:	2.121007625
Total K:	12.59525812

7x a week:
Total NO3:	17.19073875
Total PO4:	2.969410675
Total K:	17.63336137

And then of course there's the water change double dosing that'll add 1 pump extra of each respective nutrient that you dose on to the total.

What bothers me about the lower tech dosing methods is that the N is being dosed over K+. It's not the N that's going to go deficient first given feeding/fish waste. I'm suspecting lower tech dosing methods of pfertz are prone to potassium deficiencies.


----------



## nfrank (Jan 29, 2005)

the numerical analysis is interesting.... and would be helpful to have for all the available products and recipes. To help relate to other plant nutrition info, it is also useful to convert the NO3 and PO4 concentrations into N and P.

To do this N= NO3*0.226 (22.6% of NO3 is nitrogen)
P= PO4*0.326 (32.6% of PO4 is phosphate)

Thus the N ratio is 4:1.

This is more P than generally provided by EI, but is consistent in the direction i was already thinking. See http://www.aquaticplantcentral.com/forumapc/general-aquarium-plants-discussions/67039-red-plants-high-tech-soil-tanks.html#post509041

Does anyone have these doses available for the other commercial products and fertilization regimes?

With this particular product, it is also possible to customize the recipe by adjusting the number of squirts


----------



## Philosophos (Mar 1, 2009)

nfrank said:


> This is more P than generally provided by EI, but is consistent in the direction i was already thinking. See http://www.aquaticplantcentral.com/forumapc/general-aquarium-plants-discussions/67039-red-plants-high-tech-soil-tanks.html#post509041


Definitely more P than EI suggests it adds, but there's some discrepancies with the weight of a tsp between Tom's own numbers, what I've weighed(no numbers handy), and what fertilator gives as a ratio. The range sits somewhere between 2-11ppm dosed, and I imagine the variation is as much because of scale and teaspoon accuracy as much as anything.

I like the post you made given that there's a severe lack of consideration for nutrients and morphology. The information available to the hobby is pretty poor as well; it's something that I'm trying to examine better.



nfrank said:


> Does anyone have these doses available for the other commercial products and fertilization regimes?


Tom's got the ADA line of fertilizers analyzed over on TBR. TPN+ was recreated at James' Planted Tank and someone over on TBR mentioned that the ukaps forum has some posts about stablizing the KH2PO4 with everything else, though I haven't hunted those posts down for myself yet.

I'd like to get into both of these myself, plus the seachem line.


----------



## bgzbgz (Jul 6, 2007)

I wasn't trying to start a debate over EI vs Pfertz. I can understand if your trying to tell us the recipe for pfertz, but that doesnt call for such a long "article". Its almost as if your making it seem more complicated than it really is for some reason.

No offense but you give comments like these:


Philosophos said:


> All pure cost criticisms aside, Pfertz doesn't do too bad in bulk considering costs. Having mixed my own stock solutions, and knowing the time it takes, the markup isn't completely unreasonable.





Philosophos said:


> I encourage those who do not feel that they can work responsibly with any of the compounds mentioned within this article to continue buying premixed fertilizers.


and it makes it sound like your trying to sell us fertilizer instead of teaching us how to make pfertz. And yes the markup is completely unreasonable when you can do the same thing for a minuscule fraction of the cost and a little bit of effort. Isn't the whole point of this article to help people make their own pfertz, as opposed to justifying the cost with packaging material and 2 minutes of labor? This really isn't rocket science.

Im not trying to sound rude but I think you should add to your disclaimer that you plan on selling liquid ferts and its not in your best interest for it to be easy to decipher/understand this "article".



Philosophos said:


> NO3: 17.19074
> PO4: 2.969411
> Pfertz Line K+: 17.63336
> PMPD K+: 17.79787


How come half the numbers in you posts don't say whether they are in ppm, percent? Are these numbers per week or per day? Are you trying to scare newbies away so they buy fertilizer at ripoff prices?


----------



## nfrank (Jan 29, 2005)

what are TBR and TPN+ ?

I think for the purposes of aquarium dosing, teaspoon/tablesoon measurements are good enough. So what if it is off by 10%.


----------



## MrSanders (Mar 5, 2006)

This is a GREAT write up and a think a VERY necessary step for our hobby to better under stand plant nutrition finding out what works and what does not, ALONG with WHY cretin systems work. That is a big problem i have always had with ADA line of ferts, no doubt their substrate system is great, combine their ferts with their substrate and there is incredible health i have seen it time and time again. But the cost is ridiculous and they keep everything all top secret so the aquarist has no better understanding from when they started why plants are healthier when adding this fert or that fert. 

Which brings me to something i have wondered about for a while, Pfertz using Urea in their nitrogen mix, and i believe Seachem does as well. Is this for of N more available to plants? possibly being a better option that KNO3 alone? If so does any one know of a easily obtainable source for urea in the form that we would need?

Another thing i noticed about the weekly values was that N and K seemed to be dosed at equal values, there seems to be contradicting info about needing as muck K and N. is this really necessary? What amounts of K per week are really needed to see healthy growth with out K deficiency?


----------



## bgzbgz (Jul 6, 2007)

Sorry for my rant above but all you really needed to say was this:

Pfertz N = 61.27g of KNO3 and 19.31g of urea to one liter of distilled water.

Pfertz P = 19.17g of KH2PO4 to one liter of distilled water.

Pfertz K = 43.97g of K2SO4 to one liter of distilled water.

All credits go to Philosophos of course but I almost feel sorry for the people who had to read through all that just to get such a small amount of information.


----------



## davemonkey (Mar 29, 2008)

Philo,

thanks for postnig those gram/tsp comparisons (I guess I should have known where to find them!  ).

I had to go back and read you first post again, so very interesting to me. Although I'm not prone to mixing up my own ferts (I usually dose solid when needed) it is very handy to know how these liquids are made and it really opens new doors to hobbiests who want to understand and know more about how/why fertilizers, in general, work in planted tanks.

Probably a side topic for later, but it's also interesting that it was suggested that low-tech tanks might suffer K defficiency when ferts are dosed according to those recommendations. I have what I consider a low-tech NPT (don't really dose much at all) and K deffiiciency is exactly what I've got. (Although, that is probably more linked to what I *don't* dose since I don't actually follow any particular regimen in that tank. )


----------



## MrSanders (Mar 5, 2006)

bgzbgz, Please keep things as non critical as you can. This is a write up to spur conversation about fertilizers and how and why certain ones, or brands work. This is not a debate, or an invitation to ASSUME a person is TRYING to do anything other than what is directly stated.

So to be as to the point as possible, if you don't have something to say to continue this thread in the direction it was meant to go, then find some where else to attack or accuse people... we DO NOT need that here on our APC forums


----------



## khanzer22 (Nov 30, 2009)

MrSanders said:


> bgzbgz, Please keep things as non critical as you can. This is a write up to spur conversation about fertilizers and how and why certain ones, or brands work. This is not a debate, or an invitation to ASSUME a person is TRYING to do anything other than what is directly stated.
> 
> So to be as to the point as possible, if you don't have something to say to continue this thread in the direction it was meant to go, then find some where else to attack or accuse people... we DO NOT need that here on out APC forums


I think bgzbgz is trying to decipher Dan's analysis... As for newbie like me, I didn't catch some of Dan's statements (I guess I hate numbers! ) to be honest until he stated the summary behind it... So thanks to bgzbgz and specially to Dan...


----------



## ashappard (Jun 3, 2006)

bgzbgz, Dan's posting detailed information here for the user community to review and it is much appreciated. Keep it civil

@nfrank : 

TBR = the barr report
TPN+ = tropica plant nutrition plus


----------



## Philosophos (Mar 1, 2009)

BGZ, I would like to reply to your criticism fairly but you and moogoo have a personal grudge with me that you've decided to drag out on to this forum. I wrote this article purely for the love of the hobby, it's the first one I've written, and as you can see from the posting over at TBR, I'm already planning on improving it. The improvements I've already planned pretty much bump off your idea of me being some sort of greedy corporate business man with ulterior motives. I really don't feel you're worth any more of my attention at this point.


----------



## bgzbgz (Jul 6, 2007)

Philosophos said:


> I really don't feel you're worth any more of my attention at this point.


I sincerely apologize to Philosophos and APC, I wasn't trying to be uncivil in any way.


----------



## MrSanders (Mar 5, 2006)

Glad we are able to be adults about it 

Now lets keep this moving in the right direction! Does any one have any comments on Urea as a N source for aquatics? is it better? or just another way to deliver N with out the added K? also are there levels to which it would become toxic to fish or inverts if it were say, used as the only source of N?


----------



## Philosophos (Mar 1, 2009)

Sorry everyone if my original post is a bear to get through. I've got some improvements for it coming, even some unit corrections from BGZ despite our disagreements.



MrSanders said:


> Does any one have any comments on Urea as a N source for aquatics? is it better? or just another way to deliver N with out the added K? also are there levels to which it would become toxic to fish or inverts if it were say, used as the only source of N?


I'd be guessing urea is more toxic to fish, being a major constituent of urine. If you want a good place to start, searching the CAS number on the EPA ECOTOX Database is a great way to get some toxicity information. There's a bit of a learning curve to using the database, but it's helped me quite a bit. If you're lucky you'll get a few NOAEL's (No Adverse Effect Level) for warm water species of fish; usually guppies and sunfish, sometimes cherry shrimp or ghosts.


----------



## Philosophos (Mar 1, 2009)

Sorry to double post, but I've updated the OP for a simpler version immediately after the preface. A few missed ppm's and a percent sign have been added in as well.


----------



## xximanoobxx (Sep 7, 2009)

Philosophos said:


> your idea of me being some sort of greedy corporate business man with ulterior motives.


Is it true you are selling fertilizer?


----------



## Philosophos (Mar 1, 2009)

Right now? I trade some fertilizers for store credit now and then; it keeps the guys plants healthy, and I get some prime or excel when I need it. As it is though, there's no company and not a cent of actual cash made off of doing this for me. I've been considering some small private sale stuff on forums as well.

Don't get me wrong, I'd love to start a company up and I have aspirations to. When I do it, and if it succeeds, I expect to see others write articles like this. Besides that, I'll even willingly leave all the numbers right out in the open to do it with regardless of what law requires. I believe in providing for a market, not artificially creating one through dishonesty. Odds are I'll be asking Greg Watson some questions on business ethics before anything ever hits the shelves.


----------



## moogoo (Mar 19, 2009)

Philosophos said:


> BGZ, I would like to reply to your criticism fairly but you and moogoo have a personal grudge with me that you've decided to drag out on to this forum. I wrote this article purely for the love of the hobby, it's the first one I've written, and as you can see from the posting over at TBR, I'm already planning on improving it. The improvements I've already planned pretty much bump off your idea of me being some sort of greedy corporate business man with ulterior motives. I really don't feel you're worth any more of my attention at this point.


our posts were not because of a personal grudge but merely an observation of the complexity you've added to the simple task of mixing liquid ferts. A task that takes a few minutes, costs very, VERY little in comparison to buying pfertz. It's easy to make something like mixing liquid ferts sound complicated and intimidating with all the numbers, ppms, percentages, etc., to the planted tank beginner or those not familiar with ferts, it can seem like a daunting task, when in reality it is not.

Mixing liquid ferts requires simple elementary level math, a $10 digital scale from ebay, dry ferts, water, and some containers. it is not as complicated as you make it seem.

if your post were to discuss the benefits or disadvantages of pfertz based on their composition, then bravo. it is worthy of dissection and discussion. However, from your comments, as quoted by bgz above, it seems to me that you want to seem like the fert guru who has a grasp on such "complicated" stuff, so that when the time comes that you do start your own line of liquid ferts for selling, people will buy from the "guru." And yes, you may deny that it is not your intention, and yes it is a bit of speculation on our part, but we all know (you, bgz, and i), your intentions as you have clearly discussed them at length with us before.

to sum up. Ferts =/= complicated. Mix them yourself for your needs and you'll save lots of money and have the right amount of everything for your particular plants.


----------



## Philosophos (Mar 1, 2009)

moogoo said:


> our posts were not because of a personal grudge but merely an observation of the complexity you've added to the simple task of mixing liquid ferts. A task that takes a few minutes, costs very, VERY little in comparison to buying pfertz. It's easy to make something like mixing liquid ferts sound complicated and intimidating with all the numbers, ppms, percentages, etc., to the planted tank beginner or those not familiar with ferts, it can seem like a daunting task, when in reality it is not.
> 
> Mixing liquid ferts requires simple elementary level math, a $10 digital scale from ebay, dry ferts, water, and some containers. it is not as complicated as you make it seem.
> 
> ...


At length? I talked about it a couple of times, yes. I admit my intentions to eventually start selling fertilizers, and you know just about nothing of my ethics. If you had a neutral opinion of me you wouldn't be putting together your little conspiracy. Go play internet police somewhere else. Other people can ask questions all day long about conflicts of interest, but I don't really expect anything honest out of you or the rest of the clique.


----------



## brenmuk (Oct 7, 2008)

I don't know if you have seen this useful page on an 'all in one solution' and pros and cons etc

http://www.theplantedtank.co.uk/allinone.htm

I usually refer to this site for algae info but there's loads of other useful stuff on there as well.


----------



## Philosophos (Mar 1, 2009)

We're discussing it in the thread over actually, and James has decided to join in on it 
http://www.aquaticplantcentral.com/forumapc/fertilizing/67084-all-one-easy-ferts.html#post509272


----------



## ashappard (Jun 3, 2006)

doh! ninja'd.. gonna check out that thread now dan.

...
...


----------



## emreutku (Oct 22, 2008)

Hi dan,

K2O = 0.83 K

So %5.1 K2O= 0.83X5.1 = %4.23 K

Wrong?


----------



## Philosophos (Mar 1, 2009)

It's right, almost exactly how I'd do the formula as well.

Thanks for catching that; It looks like I copied down the molarity wrong between a text file and spreadsheet. I'll adjust the numbers and get a mod to edit


----------



## barbarossa4122 (Dec 31, 2009)

Philosophos said:


> Oh, you'll also find standard EI sits at higher PPM's, especially for the PO4 which is more like 11ppm or so. Doing macros in at the same time as the micros and some of the stability issues with the PO4 is also something I wanted to get into.


Hi,

11ppm/week of PO4 ? I am dosing about 7ppm(via Fleet) and I am thinking that is a little too much. Dan, are you sure?


----------



## Philosophos (Mar 1, 2009)

Ya, 11ppm... higher depending on how you work the numbers. PO4 from salts really isn't that toxic; inorganic compounds tend not to be. You'd be surprised how many compounds with fertilizer applications you've consumed. KCl is in "light" salt, CaCl2 for your beef jerky and sushi nori, oh and that KH2PO4 goes right into Gatorade 

As with all things, I've found it's best to make guesses but not solid assumptions. If you head over to the EPA ECOTOX database you'll probably find a PO4-related salt that shows just how much fish or plants related to the hobby can handle (look for NOEL/NOAEL).


----------



## barbarossa4122 (Dec 31, 2009)

Philosophos said:


> Ya, 11ppm... higher depending on how you work the numbers. PO4 from salts really isn't that toxic; inorganic compounds tend not to be. You'd be surprised how many compounds with fertilizer applications you've consumed. KCl is in "light" salt, CaCl2 for your beef jerky and sushi nori, oh and that KH2PO4 goes right into Gatorade
> 
> As with all things, I've found it's best to make guesses but not solid assumptions. If you head over to the EPA ECOTOX database you'll probably find a PO4-related salt that shows just how much fish or plants related to the hobby can handle (look for NOEL/NOAEL).


Thanks , Dan.


----------



## oscarjamayaa (Dec 12, 2009)

Thanks a lot for this porst Philosophos .. I´ll start my own fetz bussines


----------



## Liquidity (May 3, 2010)

Philosophos, thanks so much for the write up. I've had planted tanks for about a year and a half now, but I'm just now starting to fertilize (my aquasoil is clearly running out of nutrients). 

I bought pfertz when I first started (but have not used them yet) for three reasons: 1) I was trying to learn a lot of things at once, and buying pfertz allowed me to put off learning about mixing ferts until I had a better understanding of planted tanks; 2) I live in a loft and do not have storage space for gallon jugs or bags of dry ferts; 3) I like the pfertz bottles - they go with my loft interior design. 

I apologize in advance for the noob question, but I have been looking for this answer on the intertubes for a while and have not been able to find it. Maybe I am not asking the right question, but what I would like to know is, "how many times do i squirt each bottle into my tank, and how many times a week do I dose?" I suspect the answer has to do with how heavily my tank is planted and obviously the water volume, but I expected to find something like, "1 pump of macros per 10 gallons 3x a week for lightly planted, 6x for heavily planted" or something like that, but I just haven't seen it.

Thoughts? Thanks in advance!


----------



## bigstick120 (Mar 8, 2005)

Has anyone tried this?
I was going to mix up a batch and play with the dosing on a few of my smaller tanks.

Im seeing different calculations for the N mixture. Ive seen.

Pfertz [N]:
KNO3 (Potassium Nitrate): 61.27523782g/L
CH4N2O (Urea): 19.3193426g/L

and

KNO3 (Potassium Nitrate): 41.50563694g/L
CH4N2O (Urea): 19.3193426g/L

So which is correct?


----------

