Diy Fert Question- Calculations

dean9922

Junior Poster
Apr 26, 2009
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Ok, so I got all my dry ferts and have been on chuck's calculator etc and am going to use just one of the ferts for an example.

KNO3

The research i've done says if you add 11 tsp or 59.4 grams in 1 litre of distilled water. 1mil of fert will raise nitrate levels in 10 gallons by 0.96ppm or for simplicity sake 1 ppm, with a target level of 5ppm.
Therefore, in my 30 gallon tank for example each mil I add will raise 0.33 ppm and to reach the target of 5 ppm I would have to add about 15.15 mil's.

My question is, am i correct or do I have to go back to school....lol

Also, in dosing this fert, do you just go ahead and add the 15 mil's right away in one shot or in several steps ex: 5 mils at 3 times per week.

I have a low level 2wpg "non" CO2 tank with anubius java fern and crypts.
It is not a heavily planted tank "yet" so not sure about the frequency of adding macros and micros to this tank and my 76 and 100 gallon.
All this is quite new to me and I do appreciate the help anyone can give.
Also special thanks Tom Barr for the help given already.
 

Philosophos

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Mar 12, 2009
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Well let's see how it works out:

KNO3:

1 potassium: ~39g/mol
1 nitrogen: ~14g/mol
3 Oxygen: ~16g/mol

So KNO3 is 61g/101g/mol NO3

59.4g*61/101 = ~35.874mg

Note that I didn't bother to convert to mg, because the number would've been divided by 1000 to figure out ml anyhow. It saves a step.

So that's ~36mg/ml in your solution by my calculations, maybe a touch higher if I didn't round atomic mass. Not sure where you're losing 2-3ml.

From there, I'd say you've probably got a column of 95-110L depending on hard and squishy stuff:

5/36*95 = ~13.194
5/36*110 = ~15.278

So your dosing looks about right. A couple ml's discrepancy between the two of us is shouldn't make a big difference in this case.

-Philosophos
 

dean9922

Junior Poster
Apr 26, 2009
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thanks Philosophos
any recommendations in regards to how ofter I should add the ferts(micro & macro) in a tank with "no" Co2 added and not lots of plants...yet......
 

Philosophos

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Tom Barr

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While 5ppm of NO3 might seem too low in some advice, cases etc, with this tank it's actually a lot.

1-2 ppm ought to be fine for NO3 from KNO3.

If you decide to use Excel or CO2, then you will add more etc.
Stick with the same light though.



Regards,
Tom Barr
 

dean9922

Junior Poster
Apr 26, 2009
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thanks Tom for responding "again"....just wonder what the difference is between using excel as compared to CSM+B trace elements.
Should I still use "excel" along with all the other ferts??????

Also was reading an article Philosophus gave me on Non CO2 and it looks like you recommend about once a week dosing (maybe twice) and 50% water change weekly. Does that sound right????

I hate to be a pain in asking so many questions....but I just don't know this stuff and boy, are you a vast wealth of knowledge.....you should seriously write a book
and call it......"ferts for dummies" lol
thanks again
 

TheKillHaa

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Oct 31, 2007
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dean9922;37753 said:
you should seriously write a book
and call it......"ferts for dummies" lol
thanks again


i prefer read Tom in a forum, rather than in a book, at least, forums are alive,
:)


but,, after all, would not be a bad idea
:D
 

Tom Barr

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As mentioned, the interactive aspect is much better than a book in many ways. But not everyone likes to interact either. Many like a book to pick up etc.

Many learn differently.
I can change errors easily and edit.
Not every issue is the same. I can update things.
Etc.

But after awhile....I can do it.
But it'll not start until after this year.
I have other fish to fry right now.

Regards,
Tom Barr