Is Pre-harvest Flushing A Myth?

[Bulldog420]

Are you guys serious?

Nobody answered why NPK values don't get reduced down.......

why isn't 1-2-3 the same as 2-4-6

Anybody know the answer?

 

[Glow]

Its been answered - read over the posts. Ratios versus percentages and while you could round down a ratio this would downgrade the actual concentration which is measured by percentage. Thus it would be unwise for a manufacturer to round down because it would make a fertiliser look less concentrated than it actually is.

 

[Bannacis]

No definitely... different sources will have somewhat different NPK etcs… Although did you stop to think that if you take a sample that = 100% so somehow someone has messed up horribly listing 204% ??

I put a 110% into my thinking...LOL

 

[Bannacis]

You've certainly got a lot of opinions. I actually think from my side of things flushing is all flushed out:)

That I do, And you are free to think the way you want, just as others are also.

 

[Bannacis]

Yep it's actually wise to stick to the actual percentages when listing NPK because it also says how concentrated a product is so while from a chemistry perspective you can say write down e.g. 6 - 2 - 6 to 3 -1 - 3 and be correctly showing the ratio you've also down rated the concentration of the product. Yeah Europe has some odd labelling compliance things going on and some labels list in unusual ways. I think though the EU standardised things pretty well but back in the day you may find labels listing both elemental and oxides. One massive problem with labelling globally is that they could never agree and create a universal standard to labelling so country to country labelling can differ. Are they listing elemental there or P as P2O5 and K as K2O? I know in the hydro industry a lot of crew list as P as P2O5 and K as K2O just to satisfy US regulations so they don't have to change labels when and if they sell in the US.

fertilizer's Ratio tells us much more about how appropriate a fertilizer is than its NPK %. 20-20-20 and 10-10-10 are both 1:1:1 ratio fertilizers, but the 20-20-20 has twice the amt of nutrients per given weight as 10-10-10. Similarly, 24-8-16 is twice as concentrated as 12-4-8, so you would use half as much 24-8-16 as 12-4-8 to make a solution of the same strength.

 

[Bannacis]

Are you guys serious?

Nobody answered why NPK values don't get reduced down.......

why isn't 1-2-3 the same as 2-4-6

Anybody know the answer?

You can reduce the ratios as you stated but the 2-4-6 will have twice the volume than 1-2-3.
It is the % of each in the container, so 2% N-4%p-6%k...reducing the ratios does not reduce the amount..
fertilizer's Ratio tells us much more about how appropriate a fertilizer is than its NPK %. 20-20-20 and 10-10-10 are both 1:1:1 ratio fertilizers, but the 20-20-20 has twice the amt of nutrients per given weight as 10-10-10. Similarly, 24-8-16 is twice as concentrated as 12-4-8, so you would use half as much 24-8-16 as 12-4-8 to make a solution of the same strength.

 

[Bulldog420]

You can reduce the ratios as you stated but the 2-4-6 will have twice the volume than 1-2-3.
It is the % of each in the container, so 2% N-4%p-6%k...reducing the ratios does not reduce the amount..
fertilizer's Ratio tells us much more about how appropriate a fertilizer is than its NPK %. 20-20-20 and 10-10-10 are both 1:1:1 ratio fertilizers, but the 20-20-20 has twice the amt of nutrients per given weight as 10-10-10. Similarly, 24-8-16 is twice as concentrated as 12-4-8, so you would use half as much 24-8-16 as 12-4-8 to make a solution of the same strength.

No, you can't reduce the ratio. You have the answer, but you added that in.....

It's not a ratio, it's a %.

 

[piehole]

20-20-20 is in fact 20% equal parts of macros.theres another 40% of other things like micros plus inert products. so if the can/bag says use 1 tsp per gallon and you change the dosage to 1/2 tsp per gal you are changing the values/ratio/% to 10-10-10. they are still equal parts but you have watered down the % by using a smaller ratio. it really is that simple. same would apply if it was in a bottle and you took the new bottle and poured some out and refilled with water,you would no longer have 20-20-20 ,could be something like 7-7-7 depending on how much water you add back lol.

 

[Bulldog420]

20-20-20 is in fact 20% equal parts of macros.theres another 40% of other things like micros plus inert products. so if the can/bag says use 1 tsp per gallon and you change the dosage to 1/2 tsp per gal you are changing the values/ratio/% to 10-10-10. they are still equal parts but you have watered down the % by using a smaller ratio. it really is that simple. same would apply if it was in a bottle and you took the new bottle and poured some out and refilled with water,you would no longer have 20-20-20 ,could be something like 7-7-7 depending on how much water you add back lol.

Did you really just state that taking a tsp of fertizer and applying that to one gallon is the same as 1/2 tsp per half gallon? That is not correct. The plant is getting twice the fertilizer, and twice the water. That isn't how this works.......



The NPK ratio tells farmers how many pounds of fertilizer per acre to apply.

Agronomist tells a farmer his crops need 100 lbs N per acre. That recommendation does not come with water volumes. Could you imagine if the farmer told the agronomist that he halfed the nutrients because he halfed the volume of water? His crops would be lacking nutrients.

That is because the NPK ratio tells farmers how many pounds of fertilizer per acre to apply, and water volume has nothing to do with it. NPK is a value of nutrients, not a ratio.

Getting it yet?

 

[Scrogger2190]

Did you really just state that taking a tsp of fertizer and applying that to one gallon is the same as 1/2 tsp per half gallon? That is not correct. The plant is getting twice the fertilizer, and twice the water. That isn't how this works.......



The NPK ratio tells farmers how many pounds of fertilizer per acre to apply.

Agronomist tells a farmer his crops need 100 lbs N per acre. That recommendation does not come with water volumes. Could you imagine if the farmer told the agronomist that he halfed the nutrients because he halfed the volume of water? His crops would be lacking nutrients.

That is because the NPK ratio tells farmers how many pounds of fertilizer per acre to apply, and water volume has nothing to do with it. NPK is a value of nutrients, not a ratio.

Getting it yet?

I think what hes trying to say is if you dont need the whole gallon of water to water the plant mix the same ratio on a smaller scale so if your plant takes a half gallon and you have 2 plants you mix a gallon at 1tsp if you have 1 plant you mix up a half gallon at 1/2tsp

 

[piehole]

Did you really just state that taking a tsp of fertizer and applying that to one gallon is the same as 1/2 tsp per half gallon? That is not correct. The plant is getting twice the fertilizer, and twice the water. That isn't how this works.......



The NPK ratio tells farmers how many pounds of fertilizer per acre to apply.

Agronomist tells a farmer his crops need 100 lbs N per acre. That recommendation does not come with water volumes. Could you imagine if the farmer told the agronomist that he halfed the nutrients because he halfed the volume of water? His crops would be lacking nutrients.

That is because the NPK ratio tells farmers how many pounds of fertilizer per acre to apply, and water volume has nothing to do with it. NPK is a value of nutrients, not a ratio.

Getting it yet?

your reading comp is not adding up. i can see how you would like to twist this in your favor to save face by using the pounds per acre model. but i said nothing of the sort. please re read what i ACTUALLY wrote lol. generally growers on this site dont use pounds per acre to feed a tent full of 3 gallon pots. we use ratios like grams per gal and teaspoons per gallon ect. and sometimes we buy products like jacks nutrients witch tell us rec dodes like 1 tablespoon per gal or 20-20-20 , but for pot farming we can change that does to 1 teaspoon per gal and effectively change that ratio/% to somewhere around 7-7-7 and grow wonderful plants.just sayin

 

[Kot]

Did you really just state that taking a tsp of fertizer and applying that to one gallon is the same as 1/2 tsp per half gallon? That is not correct. The plant is getting twice the fertilizer, and twice the water. That isn't how this works.......

Lol, you serious?

 

[Bulldog420]

your reading comp is not adding up. i can see how you would like to twist this in your favor to save face by using the pounds per acre model. but i said nothing of the sort. please re read what i ACTUALLY wrote lol. generally growers on this site dont use pounds per acre to feed a tent full of 3 gallon pots. we use ratios like grams per gal and teaspoons per gallon ect. and sometimes we buy products like jacks nutrients witch tell us rec dodes like 1 tablespoon per gal or 20-20-20 , but for pot farming we can change that does to 1 teaspoon per gal and effectively change that ratio/% to somewhere around 7-7-7 and grow wonderful plants.just sayin

Sorry dude. A gram per gallon is completely different than pounds per acre. You do understand this right? Your not just trolling me?

You are talking dosage. I am talking pounds per acre, which is what NPK represents. Do you guys think commercial farmers mix up their nutes by reading a bottle? SOmething that says 1tsp per gallon? LOL. Really?

Then ask yourself, do you think NPK ratios were invented for bottled nutrients? Closet growers?

Come on guys, really? You are being serious and not trolling?

 

[Glow]

Sorry dude. A gram per gallon is completely different than pounds per acre. You do understand this right? Your not just trolling me?

You are talking dosage. I am talking pounds per acre, which is what NPK represents. Do you guys think commercial farmers mix up their nutes by reading a bottle? SOmething that says 1tsp per gallon? LOL. Really?

Then ask yourself, do you think NPK ratios were invented for bottled nutrients? Closet growers?

Come on guys, really? You are being serious and not trolling?

"You are talking dosage. I am talking pounds per acre, which is what NPK represents." Nope NPK represents NPK (Nitrogen, Phosphorous, Potassium).

And nope, no hydroponic grower talks in pounds per acre so I expect you are applying completely the wrong units of measurement for this forum. Only farmers talk pound per acre or perhaps very large outdoor growers with a farming background or farming knowledge who are growing directly in soil (and not pots otherwise pounds per acre is redundant).

Surely this thread is all flushed out by now. And BTW the imperial system is retarded:-) What in hell is a teaspoon per gallon? Jesus....4.93 milliliters in a US teaspoon, 5.92 mL in an imperial teaspoon, 5 mL in a metric and Australian teaspoon. I.e. how big is that teaspoon? Surely it better to learn metric and use grams per litre where talking powder compound ferts??!!!

 

[MIMedGrower]

What’s asinine here is hydroponic liquid nutes measured in ml. Per gallon (yeah that makes sense) and in a 700ppm conversion for ec.

Pounds per acre directions are listed on bagged powdered nutes for broadcast applications. Small bags still have grams per gallon listed.

 

[Glow]

What’s asinine here is hydroponic liquid nutes measured in ml. Per gallon (yeah that makes sense) and in a 700ppm conversion for ec.

Pounds per acre directions are listed on bagged powdered nutes for broadcast applications. Small bags still have grams per gallon listed.

Lol yup... mls per gallon is about as daft as it gets... And ppm is all wrong also. All ppm meters measure EC and then run a conversion program to convert to ppm. And there is no universal standard so is 1 EC 500 ppm or is it 640 ppm etc?

 

[MIMedGrower]

Lol yup... mls per gallon is about as daft as it gets... And ppm is all wrong also. All ppm meters measure EC and then run a conversion program to convert to ppm. And there is no universal standard so is 1 EC 500 ppm or is it 640 ppm etc?

Well in any scientific or commercial application I have seen 1ec is 500 ppm. Just not on hobby nutes intended for weed growers. Lol.

 

[Glow]

Well in any scientific or commercial application I have seen 1ec is 500 ppm. Just not on hobby nutes intended for weed growers. Lol.

No that is only correct in the US. The standard in Europe is 1 EC = 640 ppm and in other countries (e.g. Australia) 700 ppm. I do consults with US growers BTW and recently I had a client say X ppm. I then said well the standard in the US is 500 ppm but could you check the conversion factor on your meter so I can be sure we are working with the right conversion factor. He's okay damn its 640 ppm. Bloody daft system. Work in EC because it is universal where ppm is not.

 

[Bannacis]

No, you can't reduce the ratio. You have the answer, but you added that in.....

It's not a ratio, it's a %.

it is a % ratio... a 3-3-3 % ratio is half of 6-6-6
% ratio...from what i read, i didn't make it up.

 

[Glow]

ratio
[ˈreɪʃɪəʊ]
NOUN

1. the quantitative relation between two amounts showing the number of times one value contains or is contained within the other.

Same in chemistry my man.. I think what is happening here is people don't quite understand what a ratio is... We've also gone over that it would be unwise for a manufacturer to reduce the ratio downwards (which is often done in chemistry) and instead remain with the percentages (reducing down would make a fertilizer appear less concentrated than it actually was)