Simple EI Dosing Calculator

[quenton]

There is a nutrient calculator (Nutri Calc) which I wrote some months ago to handle my own tanks. I have put it up on our company web site, there is a link below.

It provides for

• saving named sets of data
• adding notes to any named set
• provides dry-dose amounts for N, K, P, Mg, Trace (either CSM+B or TMG)
• it takes into account (and shows) K from KNO3 and KH2PO4
• it allows input and saving of target amounts and source-water amounts as ppm
• it allows for N times per week dosing, and has an EI Dosing flag that biases the results towards tom barr's recommendations.
• the base formulae were derived from results using a number of existing calculators which have been deemed correct but which have idiosynchroses in use
• it is a "released" version, but is also a work-in-progress and I am happy to respond to change or bug requests. Since end-user-apps are my job and my other love (other than fishies) I look forward to suggestions

The download is 5Mb (sorry about that, its written in Smalltalk and has to include the VM). I know it works on Windows-XP, it should work on Win-95, and it has been briefly tested on Win-2000/2003. I should also work on Win-NT.

The download is a quick windows-install.

http://www.CherniakSoftware.com/homepage/Data/NutriCalc.exe

You can PM me for support, or you can send mail to
[email protected]


V1.2 initial release
V1.2.1 note on 50% weekly water changes, saves last window location

 

[Tom Barr]

Re: Simple EI Dosing Calculator

Thanks Quenton!

It seems we have a number of very good folks here that all have done various fertilizer cals, we might all pool together, we had suggested this prior,
I got side tracked and did not get folks brought together to complete it fully.

A monster version and then a lite version for folks not itnerested in the more advanced functions might be appropriate. Feeback from folks that have made the on line cals might be the most useful folks for improving the them for better utility for folks here.

We can repay you folks with plenty of ferts/plants etc, perhaps other things with real cash value.

Thanks

Tom Barr

 

[quenton]

Re: Simple EI Dosing Calculator

Thanks Quenton!

It seems we have a number of very good folks here that all have done various fertilizer cals, we might all pool together, we had suggested this prior,
I got side tracked and did not get folks brought together to complete it fully.

A monster version and then a lite version for folks not itnerested in the more advanced functions might be appropriate. Feeback from folks that have made the on line cals might be the most useful folks for improving the them for better utility for folks here.

We can repay you folks with plenty of ferts/plants etc, perhaps other things with real cash value.

Thanks

Tom Barr

Yuk -- its just fun! more so than when I build end-user-apps for work, although that's fun too

 

[quenton]

Re: Simple EI Dosing Calculator

Updated by request to have an option to show dosage in
grams-dry instead of tsp dry.

http://www.cherniaksoftware.com/homepage/Data/NutriCalc.exe

.

 

[TexasRock]

Re: Simple EI Dosing Calculator

Quenten,

You have TMG as your trace mix... can I use the same amounts if I mix my CSM+B (1 Tbsp) in 500mL of water?

Keith

 

[quenton]

Re: Simple EI Dosing Calculator

Quenten,

You have TMG as your trace mix... can I use the same amounts if I mix my CSM+B (1 Tbsp) in 500mL of water?

Keith

OK -- I will add that as an option.

You will need more than that. If you are disolving in 500ml of water, and want to get to the same strength as TMG you will want 3 tablespoons into the 500ml. Actually that gives, by may calculations, a solution just very slightly stronger than TMG, say 5% -- but that is well within the accuracty of TMG dosing by that fancty 500ml two-cap bottel, so I think that is fine.

I used to use CSM+B -- I just dosed it like the rest of my ferts. I got a bottle of water, added the amount (in my case 1/4tsp for my two tanks total), then dumped part of the water into each tank. I had previously put duct tape on the bottle to show the proportions.

 

[TexasRock]

Re: Simple EI Dosing Calculator

Quenton,

Based on your calculator... for my 100 gallon tank (probably closer to 105 gallons water volume with my 15 gallon sump) , I should be dosing...

1 tsp KNO3
3/8 tsp K2SO4
1/4 tsp KH2PO4
20 mL CSM+B (when I mix 3 tbsp in 500ml water)

but when I look at Toms EI Index... it says those numbers are a little low... so I'm still a little confused.

 

[quenton]

Re: Simple EI Dosing Calculator

Quenton,

Based on your calculator... for my 100 gallon tank (probably closer to 105 gallons water volume with my 15 gallon sump) , I should be dosing...

1 tsp KNO3
3/8 tsp K2SO4
1/4 tsp KH2PO4
20 mL CSM+B (when I mix 3 tbsp in 500ml water)

but when I look at Toms EI Index... it says those numbers are a little low... so I'm still a little confused.

Two comments

• Tom's numbers are not linear when they hit the 100-125 range, I had checked against the smaller tanks (a number of them), but not against the 100-125.
• Tom is is giving a range (100 - 125) so his numbers need to work for 100 and for 125, so they are approximations. You are at the low end, so figure that the numbers at 100 will be somewhat lower.

That said, my numbers for 125 are still a bit lower than tom's 100-125.

So the question remains -- do we need more for larger tanks? or is it just that all these numbers are approximations?

 

[TexasRock]

Re: Simple EI Dosing Calculator

Quenton,

I understand... thank you! I will put my water volume at 110 in your fert calculator and use those quantities... that way if I'm a little "over" it is ok. I'd rather be a little over than a little under and be deficient.

Thanks for your replies!

Keith

 

[turbomkt]

Re: Simple EI Dosing Calculator

TexasRock,
Your numbers are almost exactly 2x what I use on my 50g. Remember that what the EI says to do is not set in stone. Every tank is different and these numbers will get you in the ball park.

Also remember that Tom has been working with lower levels but constant ratios like 7:1 or 8:1 for N (14ppm of NO3 and 2ppm of PO4 for 7:1).

 

[quenton]

Re: Simple EI Dosing Calculator

TexasRock,
Your numbers are almost exactly 2x what I use on my 50g. Remember that what the EI says to do is not set in stone. Every tank is different and these numbers will get you in the ball park.

Also remember that Tom has been working with lower levels but constant ratios like 7:1 or 8:1 for N (14ppm of NO3 and 2ppm of PO4 for 7:1).

Agreed, but it does provide ballpark values to start with, and that is what the calculator is intended to provide. I am surprised though that you are only dosing 1/2 of the EI ballpark values??

 

[TexasRock]

Re: Simple EI Dosing Calculator

Quenton,

Could I make a solution of my N,P,K similiar to the CSM+B? That way I can dose it a little easier.

Keith

 

[Wet]

Re: Simple EI Dosing Calculator

Very nice, quenton.

 

[Wet]

Re: Simple EI Dosing Calculator

Did some quick checks and the calc for dosage to ppm is incorrect:

your calc says:
7.43g KNO3 in 50gal water volume = 18.3ppm NO3 (with 20ppm target)

by hand (I am using mass percentage for compounds) says:
(7430mg KNO3 * 0.6127mg NO3/mg KNO3) / (50gal * 3.785L/gal) = 24.05mg/L (ppm) NO3

calc says:
2.10g KH2PO4 in 50gal water volume = 3.2ppm PO4 (with 3ppm target)

hand:
(2100mg KH2PO4 * .6979mg PO4/mg KH2PO4) / (50gal * 3.785L/gal) = 7.744ppm PO4

By hand calcs coincides with Chuck's calc for what its worth. Densities for tsp/grams conversion is also incorect according to Chuck's Calc and Steve Pituch's page: http://users.ev1.net/~spituch/Chemicals/chemicals.html

Joe

 

[quenton]

Re: Simple EI Dosing Calculator

Quenton,

Could I make a solution of my N,P,K similiar to the CSM+B? That way I can dose it a little easier.

Keith

Sure -- I don't the shelf life, so I wouldnt't make too large a solution -- I have no ideal what the limits might be.

Figure, for example, 10 weeks, since the dosing is 3x per week, you will want 30x the the amount shown in the right-hand column. Disolve it in say 600 ml of water, and then use 20ml per dosing. That is 30 doses (3 for each of the 10 weeks) at 20ml per dose which is the full 600ml solution you made.

Or if you want to do 20 weeks, you could take 60x the dosage indicated, disolve it in 1200ml of water and still dose 20ml each dosing day. That is 60 doses at 20ml per does or the full 1200ml solution you made.

You can do your own amounts and math, but its easy to make an error. I worked the above out 3 or 4 times to be sure I had it right.

 

[quenton]

Re: Simple EI Dosing Calculator

Did some quick checks and the calc for dosage to ppm is incorrect:

your calc says:
7.43g KNO3 in 50gal water volume = 18.3ppm NO3 (with 20ppm target)

by hand (I am using mass percentage for compounds) says:
(7430mg KNO3 * 0.6127mg NO3/mg KNO3) / (50gal * 3.785L/gal) = 24.05mg/L (ppm) NO3

calc says:
2.10g KH2PO4 in 50gal water volume = 3.2ppm PO4 (with 3ppm target)

hand:
(2100mg KH2PO4 * .6979mg PO4/mg KH2PO4) / (50gal * 3.785L/gal) = 7.744ppm PO4

By hand calcs coincides with Chuck's calc for what its worth. Densities for tsp/grams conversion is also incorect according to Chuck's Calc and Steve Pituch's page: http://users.ev1.net/~spituch/Chemicals/chemicals.html

Joe

If you want to compare this to say chucks calc - turn off the "EI Dosing" flag, which biases things based on tom barr's suggested amounts which, among other things, take into account some amount of uptake.

You will find that the KNO3 amounts match.

Again, with EI-Dosing turned off, you should find that the KH2PO4 amounts match too.

Beware when using Chuck's Calc -- exit and restart it for each nutrient you want to check, otherwise the results change as you move from nutrient to nutrient and back again.


You may argue with the EI-Dosing biasing, but if I want to go by Tom Barr's suggested amounts, I need that -- and I do use it for 2 tank sizes right now, 2 more to come.

 

[Wet]

Re: Simple EI Dosing Calculator

Even with EI dosing turned off, your ppm from dose is incorrect, though grams to reach target is correct. For example:

Your calc says:
6.18grams of KNO3 in 50gals gives 12.6ppm NO3 from KNO3.

hand:
(6180mg KNO3 * 0.6127mg NO3/mg KNO3) / (50gal * 3.785L/gal) = 20.01mg/L (ppm) NO3

I am not arguing with biasing it towards EI, but I am assuming your goal is to have the data the calc outputs to be accurate, and would like bug reports. I am only using Chuck's Calc as a check for calcs by hand, again fwiw.

What is your formula to calculate dose from target with the 50% water change/EI? Why does it overestimate NO3 by ~30% but PO4 by ~125%?

 

[quenton]

Re: Simple EI Dosing Calculator

Even with EI dosing turned off, your ppm from dose is incorrect, though grams to reach target is correct. For example:

Your calc says:
6.18grams of KNO3 in 50gals gives 12.6ppm NO3 from KNO3.

hand:
(6180mg KNO3 * 0.6127mg NO3/mg KNO3) / (50gal * 3.785L/gal) = 20.01mg/L (ppm) NO3

I am not arguing with biasing it towards EI, but I am assuming your goal is to have the data the calc outputs to be accurate, and would like bug reports. I am only using Chuck's Calc as a check for calcs by hand, again fwiw.

What is your formula to calculate dose from target with the 50% water change/EI? Why does it overestimate NO3 by ~30% but PO4 by ~50%?

No question I am looking for bugs -- and thank you for persisting.

I think I see what you are looking at. NO3 is provided by 3 things, KNO3, K2SO4 and KH2PO4.

For your testing, ignore the the 2 gray fields marked KNO3 and KH2PO4 which show 12.6 and 1.4. The image you attached shows 20ppm as the target NO3, which is provided by the KNO3. The KNO3 also provides 12.6ppm of K which is taken into account inthe K calculations.

So if you use chuck's or mine, you get 20ppm provided by about that 6.18 grams of KNO3.

How am I calculating -- I am table driving it. My tables indicate the ppm provided by 1tsp in 100g. Then I just modify that based on the gallons and the ppm desired. Its simple, and the table has two entries, one to be used with and one without the EI-Dosing flag set.

I compute "tsp" (since that is what I had started out to do), keeping 4 dec places, and table drive a conversion to grams. That last is a bit sleezy perhaps, but since I had "tsp" to start with it was simpler.

The "tsp" is then run through a fraction generator I wrote for work, that tries to create human-oriented fractions (n/8, n/16 rather than n/23 or n/7) by using a specified accuracy requirement. I have seen it generate n/32 for some cases

 

[Tom Barr]

Re: Simple EI Dosing Calculator

I support the use of dosing calculators, but maybe I'm old school, I never use them :gw

I do it by hand.
Maybe it's easier to make mistakes that way also? :gw

Hehe, I like to figure it out that way.
I also double check things a few times and make sure the answer makes sense.

The need to check the calculations is definitely a must though either way.
The calculator looks neat anyway


Regards,
Tom Barr

 

[quenton]

Re: Simple EI Dosing Calculator

New version adds

1. Calcium (not there before)
2. Results in "tsp" or "grams"
3. Added a linear bias to make this better match Tom's EI Light dosing schedule which is not exactly gallon multiples as tank sizes increase
4. Hilites the Macro Names or the Trace Names based on which day of a 7 day dosing cycle one is on - to indicate which should be dosed that day (optional)

Caclulator at: http://www.cherniaksoftware.com/homepage/Data/Nutricalc.exe