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Discussion Starter #1
I’ve been using the Rotala butterfly calculator the passed weeks but I’ve been wondering If I’m using it correctly.
I’m trying to dose 12 ppm of nitrogen weekly to 5 gallons for water changes, the only option I have to choose is KNO3, and To reach 12ppm nitrogen is telling me to add 370 milligrams, but then it clearly says:

NO3 12ppm
N 2.71
K 7.57

Does this mean I’m only adding 2.71 of nitrogen and not 12 ppm like I want?
It’s confusing cause it doesn’t say “KNO3 12ppm”, it says NO3 12ppm which is nitrogen but then it says “N” 2.71 so is nitrogen 12 or 2.71 ppm? If nitrogen is only 2.71 and potassium 7.57 then I would obviously need to dose more to reach 12ppm if nitrogen right?
 

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You are using it correctly. You're adding 12 ppm of nitrate, which is equivalent to 2.71 ppm nitrogen.

Why do you wish 12 ppm of nitrogen? That's equivalent to 53.1 ppm of nitrate, and for planted tanks we generally strive for an upper limit of 10 ppm nitrate.
 

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I’ve been using the Rotala butterfly calculator the passed weeks but I’ve been wondering If I’m using it correctly.
I’m trying to dose 12 ppm of nitrogen weekly to 5 gallons for water changes,
well, it depends what you want to achieve. are you trying to dose 12ppm to the 5 gallons you use for weekly water changes? or do you want to dose 12ppm in your 5 gallon tank per week?
if the former, may i respectfully ask why? and if the latter, you need to enter 4ppm (if you dose 3x/week), not 12.
 

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Just to clarify a little further: Nitrogen is a gas. Since you can't just add straight nitrogen to a tank, it has to be bound in other molecules to use as a Fert. And it comes in many forms. For example:

NO3 (nitrogen and oxygen) is nitrate, which is what a lot of people consider to be "nitrogen" in an aquarium. The plants can use the nitrogen thats in Nitrate.
NH4 (nitrogen and hydrogen): Ammonium. Plants actually prefer this over nitrate.
NH3 (nitrogen and hydrogen): Ammonia. Plants can use this for a nitrogen source as well.
etc etc

All of the fertilizer dosings for aquariums are based on NO3 (nitrates), not pure nitrogen. So if your target is 12ppm nitrates, it's 12ppm nitrates. Don't worry about the actual N component as that's not really anything useful to you unless you are mixing other nitrogen forms with your nitrates (like if you were mixing NO3 and NH4, which is actually how it's mixed in Seachem Nitrogen liquid fert, then you need to account for the N in the NH4 because it won't show up on a nitrate test).
 

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Discussion Starter #5
Thanks for clearing that up, lol yeah I just want 12 ppm nitrates I just thought nitrates/nitrogen was the same but I understood now. I’ve been having tanks for years even reef tanks just never got so deep into it, I’m trying to dose everything a different way than before. But yeah I just wanna dose around 12 ppm nitrates every week not nitrogen. I’m trying to bring out the reds on my plants a bit more.

This dose is for my 20(with rocks and all prolly like 15 gallons)gallon tank, and I do 5 gallon water changes once a week. If I dose once a week what is the best way to do it? I use plain ro di water, idk if I should calculate 12ppm nitrates for the 5 gallon jug and add the 12 ppm nitrates Like that, or calculate 12ppm nitrates for my 20 gallon tank every time I do the water change? Having trouble explaining my self but I think y’all understand
 

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This dose is for my 20(with rocks and all prolly like 15 gallons)gallon tank, and I do 5 gallon water changes once a week. If I dose once a week what is the best way to do it? I use plain ro di water, idk if I should calculate 12ppm nitrates for the 5 gallon jug and add the 12 ppm nitrates Like that, or calculate 12ppm nitrates for my 20 gallon tank every time I do the water change? Having trouble explaining my self but I think y’all understand

If 12ppm is your target nitrate range for your tank, then you need to figure out your nitrate level in your 20 gallon AFTER you do your 5 gallon water change. So, water change, then test nitrates. If you're showing 0 nitrates after your water change, you'll need to dose for 12ppm in 20 gallons. Or, if your water test shows 6ppm nitrates after your water change, then you only need to dose 6ppm in 20gallons to hit your overall 12ppm target.

Depending on your plants and setup, 12ppm in a week might not even be enough. I have a ton of water wisteria in my low-tech tank, and it eats about 20ppm nitrates over the week.
 

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Discussion Starter #7
I was trying to dose similar to Dennis Wong’s tank, I’m not sure if you’ve seen it on YouTube. And yeah I will have to test for nitrates, I was just trying to dose once a week without testing but I know every tank is different. What’s your tds? I was dosing more before and my tds was going up to 400, I’m trying to keep it at 255 or less. But yeah hopefully my plants don’t show deficinecys, I have Amazonia soil though so I’m sure they get some nitrates from there too. I even used a bit of ada power sand.
 

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Your using a dry compound, potassium nitrate, when it dissolves in water it breaks bond between them and you end with ?ppm of K and ?ppm of NO3 in solution. That’s what calc is showing you.

The N is only showing you how much available nitrogen it contains that the plants can use. Plants during uptake actually break the bond between the N and the O3 and absorb the N, plant is not intaking NO3.

Available nitrogen can be comprised of ammonia, ammonium and nitrate. Plants actually prefer absorbing ammonia compounds but in aquarium they can be detrimental to fauna in higher levels. If you’ve got a plant only tank you can dose pure ammonia and plants will have all the nitrogen they need.
 
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