Cautionary note on using online nutrient calculators

Wet

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Great news. I see what you mean about Fe (now fixed). B looks right though for Vimi using http://www.vimi.lt/products/vimi-all-in-one/ ? Am I misreading?

For Tropica Plant Nutrition and Plant Nutrition + these are the values I have.
Code:
Tropica Plant Nutrition +:
  N:      1.34
  NO3:    5.90
  P:      0.10
  PO4:    0.3065
  K:      1.03
  Mg:     0.39
  S:      0.91
  B:      0.004
  Cu:     0.006
  Fe:     0.07
  Mn:     0.002
  Mo:     0.002
  Zn:     0.002
  urea:   yes
  target: NO3
Tropica Plant Nutrition:
  K:      0.79
  Mg:     0.39
  S:      1.01
  Fe:     0.07
  Mn:     0.04
  B:      0.004
  Cu:     0.0006
  Mo:     0.002
  Zn:     0.002
  target: Fe

In searching their site I do not concentrations. If you have a link I am happy to adjust those concentrations on the calculator (or again feel free to create an account and hit "edit" here! https://github.com/flores/yet-anoth...blob/master/constants/commercial_products.yml )

Also, in checking Tropica's site, I no longer even see TPN+ or TPN but rather Plant Growth Premium Fertilizer and Plant Growth Specialized Fertilizer. Is this just a name change or are they whole new products? If it is a name change I'll update the calculator, or if it's new products we should add them.

Thanks!

- - - Updated - - -

Great news. I see what you mean about Fe (now fixed). B looks right though for Vimi using http://www.vimi.lt/products/vimi-all-in-one/ ? Am I misreading?

For Tropica Plant Nutrition and Plant Nutrition + these are the values I have.
Code:
Tropica Plant Nutrition +:
  N:      1.34
  NO3:    5.90
  P:      0.10
  PO4:    0.3065
  K:      1.03
  Mg:     0.39
  S:      0.91
  B:      0.004
  Cu:     0.006
  Fe:     0.07
  Mn:     0.002
  Mo:     0.002
  Zn:     0.002
  urea:   yes
  target: NO3
Tropica Plant Nutrition:
  K:      0.79
  Mg:     0.39
  S:      1.01
  Fe:     0.07
  Mn:     0.04
  B:      0.004
  Cu:     0.0006
  Mo:     0.002
  Zn:     0.002
  target: Fe

In searching their site I do not concentrations. If you have a link I am happy to adjust those concentrations on the calculator (or again feel free to create an account and hit "edit" here! https://github.com/flores/yet-another-nutrient-calculator/blob/master/constants/commercial_products.yml )

Also, in checking Tropica's site, I no longer even see TPN+ or TPN but rather Plant Growth Premium Fertilizer and Plant Growth Specialized Fertilizer. Is this just a name change or are they whole new products? If it is a name change I'll update the calculator, or if it's new products we should add them.

Thanks!
 

Petex

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I still noted that Po4, Fe, B had some differences, but about Vimi Boron it just seem to be the rounding issue
(1ml@50L will add 0,00175ppm ---> calculator seems to round up to 0,0018ppm)

Tropica Plant Nutrition liquid+ Deklaration:
W/W% (Gew./Gew.%, P/P%):
N 1.34%, P 0.10%, K 1.03%, Mg 0,39%, S 0.91%, B 0.004%, Cu 0.006%, Fe 0.07%, Mn 0.04%, Mo 0.002%, Zn 0.002%.

TPN:
K 0,80%, Mg 0,39%, S 0,91%, B 0,004%, Cu 0.006%, Fe 0.07%, Mn 0.04%, Mo 0.002%, Zn 0.002%.

So look at yours written values,
TPN: You added 1x zero too much for Copper, it contains 0,006% cu (not 0,0006%)
TPN+: Manganese should be 0,04% and not 0,002%


Is this just a name change or are they whole new products?
Imo, all the same stuff. (Tropica Master Growth -> Plant Nutritiion Liquied --> Premium fertiliser)
Seems they like to rename, unfortunatly their products didnt change or gett improvments .... just their prices get improvments.

or again feel free to create an account and hit "edit" here!
I would do if I could, but my english is not that good enough and like you see it is diffucult to understand what I wanna tell (you), too.
 

Wet

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Thank you Petex. I made those changes. If you get time, please verify that I got the values correctly?

Idea: would you like a checkbox that said "do not round values" that would give you the full results of the calculation without rounding regardless of how many digits there are past the decimal? If so the calculator will not be able to understand significant digits, but maybe that feature would be useful for some folks? It would be a checkbox that is off by default. What do you think?

- - - Updated - - -

Thank you Petex. I made those changes. If you get time, please verify that I got the values correctly?

Idea: would you like a checkbox that said "do not round values" that would give you the full results of the calculation without rounding regardless of how many digits there are past the decimal? If so the calculator will not be able to understand significant digits, but maybe that feature would be useful for some folks? It would be a checkbox that is off by default. What do you think?
 

Petex

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I guess most folks are still looking how much iron a fertilisier adds, but since yours calculator also lists the other nutritions, I think the given results also for the other nutritions should be accurate. Otherwise it would be senseless.
1ml Tropica adds in a 11L tank for example 0,0054ppm Cu and if such values gets rounded up to 0,01ppm - thats imo not so good, because such rounded results looks like it adds 2x more (but thats at last not true)
So yes, imo it would be a very great service if you could add an option to get "accurate & non-rounded results."
(for that few folks who wants to know it more closer :D )
 
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Wet

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Hi Petex.

I am sorry for my delay.

I have added the "Do not round" checkbox to http://rota.la -- if you like it I will leave it in and move it to calc.petalphile.com and the mobile interface, too. (Right now it is not there.)

Unfortunately I only have the English translation for this as well and so we may need to reach out to folks for an updated translation.

Let me know what you think!
 

Petex

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thank you very much for the great service. :)
May it be possible to get the unrounded results displayed perhaps max. 5 or max. 6 numbers behind the point (like this @ X.XXXXX )?
5 or max. 6 numbers usually match even to the "lowest added" nutritions and would make the readings imo easier then displaying full 16 numbers behind the point.

About translation:
I can still translate in German language if this would help you?
 
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Wet

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No problem. I would very much appreciate the translation, thank you!

My concern about rounding to x digits past the decimal is that it's still rounding, and based on experience folks will ask for that number to keep moving to their needs (regardless of the number of significant digits on the input).

So, what if we turn it into an input the user can select? http://rota.la now lets you pick 1-6 or no numbers past the decimal, so you and other users can choose what you prefer based on your needs? I am thinking an advantage would be for people who do not need precision and would prefer whole numbers (which folks have requested in the past by saying the calculator outputs too many numbers).

What do you think? (Question for Petex and anyone else following this thread)
 
Mar 20, 2013
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I'm wondering why the outputs for certain nutrients double. For example, a couple of weeks ago, MKP was twice what it should have been. It's since been corrected, but this doubling has occurred at least twice that I've noticed, the previous time mentioned earlier in this thread. Is there any way to lock down these numbers so that it doesn't double when a nutrient calculation is updated? I'm sure some visitors have probably used the calculator and have gone away thinking they were dosing correctly, only to be dosing half what they intended.
 

Wet

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Solcielo lawrencia;127724 said:
I'm wondering why the outputs for certain nutrients double. For example, a couple of weeks ago, MKP was twice what it should have been. It's since been corrected, but this doubling has occurred at least twice that I've noticed, the previous time mentioned earlier in this thread. Is there any way to lock down these numbers so that it doesn't double when a nutrient calculation is updated? I'm sure some visitors have probably used the calculator and have gone away thinking they were dosing correctly, only to be dosing half what they intended.

Hi Solcielo,

The doubling you mentioned is because certain nutrients had their actual values updated, and in the cases you mention it wasn't actual elemental percentages but teaspoon/density weights. This is my fault because I accepted a change without validating the numbers.

Normally the way it works is anyone in the community can contribute updates (be it adding new products or correcting values with manufacturer updates or correcting bugs) or translations. I then used to go all around the Internet -- mostly here, APC, TPT, UKAPS, SCaPE, AGA forums, etc -- and shared the changes, then would follow up on the threads to look for user feedback or corrections, much like this thread. The source of truth for the current code is in those links earlier.

However, lately I've just been away from the hobby and pretty burned out on forums, but folks are still kindly (thank you!) contributing products and updates. In the case above with incorrect values that doubled the results, I got the request on March 26th, asked the person if they could update various forums until I got around to it, then didn't really look at it again until April 9th. At that point I just pushed the update without validating the results or checking around the forums. I'm sorry for that. zorfox found and corrected this on May 8th.

I don't really want to limit or freeze values because if I did new products and additions would slow down too much. For example, in just the past month alone josephsydee has added Amgrow and zorfox has added MiPlus, MiPlus Pro, Florapride, and corrected the solubility of Plantex. zorfox is a beast and a big contributor but no one person can watch all this stuff year after year and stay up to date.

So maybe the best thing to do would be to just get better about making big updates to large use items (like KNO3, etc) after doublechecking the values and updating forums. Then we can still get these new products in with less overhead since they're new and probably not on any other online calculators anyway. But that's just an idea and feedback is appreciated -- really the reality is I probably won't spend consistent hours checking forums and widely supporting this thing until I get back into the hobby with more dedication and a better tolerance for some behavior on forums :)

Another idea is I could add something to the calculators that says "nutrients last updated on . contact wet if there are any issues." We'll need translations for other languages, but at the very least maybe that can expose changes to users in a better way if numbers do turn wonky. What do you think?

Other ideas are appreciated, and again thank you for sticking through that mistake.
 

Petex

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So, what if we turn it into an input the user can select? http://rota.la now lets you pick 1-6 or no numbers past the decimal,
This is a very great idea and really a perfect solution that fits for everyone.
Thank you so much. :)

About translation,
just let me know what page or words/sentences or you need to translate.
 

Wet

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Hi fablau.

Thanks and I did miss that thread. Replying now!

Petex,

That sounds great -- I will just leave it for a few more days and see if anyone complains, and if not will put it on calc.petalphile.com and the mobile calc, too. Thanks so much for your feedback.

re translation: May I have the translation for "Round to digits past the decimal" that would fit in that spot to the left of the numbers? Better and more understandable phrasing is also appreciated!
 
Mar 20, 2013
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I'm curious about how dry fertz are calculated if using teaspoons instead of dry weight. Some fertz, such as KH2PO4, have different forms and can be more powdery than granular. I'm sure this affects the weight as the powdered form is denser than the granular form. Would this affect the calculator's output?
 

Wet

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Hi Solcielo,

Yes, if the weight moves so will the calculator's output. So stuff that is significantly different from the teaspoon to gram conversions will move the output. Since a scale skips the conversion, using mg/g input will always be more accurate than converting from teaspoons. Of course, this is only talking about the calculator -- experience shows such differences probably won't matter for your plants and animals.

I think getting a cheap scale can be very useful (I think they're fun and use it for all sorts of stuff) and even relatively cheap scales are more than good enough for aquariums.

Also if there's interest we can put in different forms of a compound for the purposes of teaspoon conversions. I thought about doing this for KNO3 as stump remover (pellets) vs from suppliers (grainy). We'd need folks to try to accurately measure teaspoon weights and those folks will need to have scales and be willing to share of course. The standard from the old APC threads collecting conversions was to measure a leveled teaspoon 10 times and post those results.

But again, that's all just to have a lot of accuracy in these numbers if that matters to the gardener (and not necessarily the garden).