Reverse Engineering everyone's nutrients

[Redoctober]

Ammonium based N tends to cause glossy dark emerald green leaves while nitrate based N tends to cause a mat light green leaves. I think that when people are thinking of N toxicity, they're usually thinking of ammonium toxicity. This is because NH4+ antagonizes K+, Ca++, Mg++, Fe++, etc, while NO3- antagonizes H2PO4-.

I guess this basically makes mono ammonium phosphate and ammonium sulfate unnecessary in hydro. All the ammonium required could be derived from calcium nitrate and the amino supplement which is 13.6-0-0. The phosphate and sulfate supplied by these two is really pretty low anyway, and could be replaced by the addition of a tiny bit of extra potassium phosphate and magnesium sulfate.

 

[Redoctober]

MisterBlah, do you happen to know the composition of the various pH up and pH downs by the different manufacturers?
Specifically AN?
They make a pretty concentrated solution which goes a long way, so I really don't mind buying a quart for $15 or so.
But if I could make the same thing for like 10 cents I'd do it unless I'd need to order some hazardous salt or watched chemical that would land me on a gov watch list

(I remember a while back I went into an auto store because they used to sell sulfuric acid (battery acid) and when I inquired about it the guy behind the counter gave me the strangest look and started asking me all kinds of questions. It was not pleasant.)

 

[Carolina Dream'n]

MisterBlah, do you happen to know the composition of the various pH up and pH downs by the different manufacturers?
Specifically AN?
They make a pretty concentrated solution which goes a long way, so I really don't mind buying a quart for $15 or so.
But if I could make the same thing for like 10 cents I'd do it unless I'd need to order some hazardous salt or watched chemical that would land me on a gov watch list

(I remember a while back I went into an auto store because they used to sell sulfuric acid (battery acid) and when I inquired about it the guy behind the counter gave me the strangest look and started asking me all kinds of questions. It was not pleasant.)

Ph down is phosphoric acid. Ph up is potassium hydroxide.

 

[ttystikk]

MisterBlah, do you happen to know the composition of the various pH up and pH downs by the different manufacturers?
Specifically AN?
They make a pretty concentrated solution which goes a long way, so I really don't mind buying a quart for $15 or so.
But if I could make the same thing for like 10 cents I'd do it unless I'd need to order some hazardous salt or watched chemical that would land me on a gov watch list

(I remember a while back I went into an auto store because they used to sell sulfuric acid (battery acid) and when I inquired about it the guy behind the counter gave me the strangest look and started asking me all kinds of questions. It was not pleasant.)

I did the same thing with battery acid and it turned out not to be that much cheaper. I didn't get any questions, though.

 

[ttystikk]

Ph down is phosphoric acid. Ph up is potassium hydroxide.

Some manufacturers use a combination of acids, it's worth a closer look

 

[churchhaze]

I guess this basically makes mono ammonium phosphate and ammonium sulfate unnecessary in hydro. All the ammonium required could be derived from calcium nitrate and the amino supplement which is 13.6-0-0. The phosphate and sulfate supplied by these two is really pretty low anyway, and could be replaced by the addition of a tiny bit of extra potassium phosphate and magnesium sulfate.

This is exactly my thinking. There's no point, imo, to ammonium phosphate and ammonium sulfate. There's no point to potassium sulfate either, because if you're using magnesium sulfate to provide Mg++, you're already getting just the right amount of sulfates. Adding any more will antagonize H2PO4- and NO3-. This is why my own formula doesn't include any of those salts.

 

[Redoctober]

I guess the next big question, and I'm not entirely sure this thread is the right place for it...but it kind of is, is: what is the proper ratio of calcium, magnesium, and sulfur?

So I've been researching this all day and haven't reached a definitive conclusion, but have been using MisterBlah's derived nutrient breakdowns to try to detect a pattern. So we can kind of figure that the magnesium to calcium ratio could be anywhere from 1:2 to 1:1. I've seen both depending on the type of crop. It seems that in most hydro formulas, the ratio is 1:2.

The real question is, what does calcium and magnesium uptake depend on? In other words, what is its limiting factor. I believe from everything I've read, cal/mag uptake is dependent in large part on nitrogen. I'll link to a few interesting university studies that are worth a look. Again, this is not a definite conclusion, just a hypothesis that I've got from the papers I read. So how do we decide on the proper ppm of calcium, magnesium, and sulfur in our mix during various stages of growth?

The calcium, magnesium, and sulfur levels seem to most closely follow nitrogen. Not exactly matching the ppm of nitrogen, but not too far off. Now many bloom formulas MisterBlah has provided dramatically cut their nitrogen levels, but retain, maybe a little less cal/mag than veg, but pretty much constant levels of cal/mag throughout. Now in the absence of nitrogen, can the calcium and magnesium be properly uptaken and utilized by the plant...perhaps, but it seems to me that bloom formulas may actually be cutting nitrogen too drastically, and a little bit would aid calcium uptake which would increase yields and fruit/flower mass.

 

[MisterBlah]

MisterBlah, do you happen to know the composition of the various pH up and pH downs by the different manufacturers?
Specifically AN?
They make a pretty concentrated solution which goes a long way, so I really don't mind buying a quart for $15 or so.
But if I could make the same thing for like 10 cents I'd do it unless I'd need to order some hazardous salt or watched chemical that would land me on a gov watch list

(I remember a while back I went into an auto store because they used to sell sulfuric acid (battery acid) and when I inquired about it the guy behind the counter gave me the strangest look and started asking me all kinds of questions. It was not pleasant.)

pH Down can be any of the following:
Nitric Acid
Phosphoric Acid
Sulfuric Acid
Citric Acid

These will ALL be in liquid form.

Phosphoric acid will usually be the cheapest. Chances are what you buy from any nutrient company is maybe 30% phosphoric acid and maybe 5-10% citric acid. You can find phosphoric acid in 75% and 85% for the same price as the 30% from a nutrient company.

pH Up can be any of the following:
potassium hydroxide
sodium hydroxide
calcium hydroxide

You can find all these in an anhydrous (solid) form. Calcium hydroxide will be the cheapest by far(you'll find it for sale at my website next week as the cheapest nutrient I'll be selling, probably <$9 for 5kg), but it has a low solubility of only 1.5-1.7g/L so you'll probably need to make larger stock solutions and use more of that stock solution to use it. However, at peak solubility, it creates a solution with only a pH of 12.6. The double hydroxide ion it has over the others is makes it worth more for your money(literally worth twice as much). The downside, as I mentioned, is the low solubility.

Potassium Hydroxide on the other hand has a much higher solubility at 1120g/L. At peak solubility you've got a basic solution of pH 15.3. It's only benefit is if you need the concentrated stock solution.

 

[MisterBlah]

This is exactly my thinking. There's no point, imo, to ammonium phosphate, ammonium sulfate. There's no point to potassium sulfate either, because if you're using magnesium sulfate to provide Mg++, you're already getting just the right amount of sulfates. Adding any more will antagonize H2PO4- and NO3-. This is why my own formula doesn't include any of those salts.

So, in regards to sulfates in hydroponics, your plants can handle pretty high sulfates without it being an issue. And if you are using magnesium sulfate, it will not really ever be an issue if you keep your magnesium around 100ppm or so. However, potassium sulfate is not useless. If you use magnesium nitrate as the magnesium source, you may instead use potassium sulfate.

 

[churchhaze]

I guess the next big question, and I'm not entirely sure this thread is the right place for it...but it kind of is, is: what is the proper ratio of calcium, magnesium, and sulfur?

So I've been researching this all day and haven't reached a definitive conclusion, but have been using MisterBlah's derived nutrient breakdowns to try to detect a pattern. So we can kind of figure that the magnesium to calcium ratio could be anywhere from 1:2 to 1:1. I've seen both depending on the type of crop. It seems that in most hydro formulas, the ratio is 1:2.

The real question is, what does calcium and magnesium uptake depend on? In other words, what is its limiting factor. I believe from everything I've read, cal/mag uptake is dependent in large part on nitrogen. I'll link to a few interesting university studies that are worth a look. Again, this is not a definite conclusion, just a hypothesis that I've got from the papers I read. So how do we decide on the proper ppm of calcium, magnesium, and sulfur in our mix during various stages of growth?

The calcium, magnesium, and sulfur levels seem to most closely follow nitrogen. Not exactly matching the ppm of nitrogen, but not too far off. Now many bloom formulas MisterBlah has provided dramatically cut their nitrogen levels, but retain, maybe a little less cal/mag than veg, but pretty much constant levels of cal/mag throughout. Now in the absence of nitrogen, can the calcium and magnesium be properly uptaken and utilized by the plant...perhaps, but it seems to me that bloom formulas may actually be cutting nitrogen too drastically, and a little bit would aid calcium uptake which would increase yields and fruit/flower mass.

3:1 to 2:1 Ca:Mg. Hard water users will want more Mg since more calcium is provided in the tap.

 

[churchhaze]

So, in regards to sulfates in hydroponics, your plants can handle pretty high sulfates without it being an issue. And if you are using magnesium sulfate, it will not really ever be an issue if you keep your magnesium around 100ppm or so. However, potassium sulfate is not useless. If you use magnesium nitrate as the magnesium source, you may instead use potassium sulfate.

I run Mg at around 50-60ppm and consider that high.

 

[ttystikk]

pH up can be any of the following:
Nitric Acid
Phosphoric Acid
Sulfuric Acid
Citric Acid

These will ALL be in liquid form.

Phosphoric acid will usually be the cheapest. Chances are what you buy from any nutrient company is maybe 30% phosphoric acid and maybe 5-10% citric acid. You can find phosphoric acid in 75% and 85% for the same price as the 30% from a nutrient company.

pH down can be any of the following:
potassium hydroxide
sodium hydroxide
calcium hydroxide

You can find all these in an anhydrous (solid) form. Calcium hydroxide will be the cheapest by far(you'll find it for sale at my website next week as the cheapest nutrient I'll be selling, probably <$9 for 5kg), but it has a low solubility of only 1.5-1.7g/L so you'll probably need to make larger stock solutions and use more of that stock solution to use it. However, at peak solubility, it creates a solution with only a pH of 12.6. The double hydroxide ion it has over the others is makes it worth more for your money(literally worth twice as much). The downside, as I mentioned, is the low solubility.

Potassium Hydroxide on the other hand has a much higher solubility at 1120g/L. At peak solubility you've got a basic solution of pH 15.3. It's only benefit is if you need the concentrated stock solution.

Great post, except you got your ups and downs backwards. Murphy rides again! Lol

 

[ttystikk]

3:1 to 2:1 Ca:Mg. Hard water users will want more Mg since more calcium is provided in the tap.

Or @MisterBlah, I use a lot of calcium, as calcium nitrate. I've noticed what looks like mag deficiency. How much epsom salt (mag sulfate heptahydrate) would I need to reach 50mg/gal of mag?

 

[MisterBlah]

Great post, except you got your ups and downs backwards. Murphy rides again! Lol

Haha! This is like East and West with me. Up/Down. When I visualize pH and acids, lower pH, I visualize it at the top and high pH at the bottom. Like a scoreboard. So, I'm not surprised I mixed those up.

 

[MisterBlah]

Or @MisterBlah, I use a lot of calcium, as calcium nitrate. I've noticed what looks like mag deficiency. How much epsom salt (mag sulfate heptahydrate) would I need to reach 50mg/gal of mag?

uhm... mg/gal? I deal in metric. mg/L

Using Magnesium Sulfate Heptahydrate, to reach 50mg/L, which is 50ppm, you need to add 0.51g/L.

 

[ttystikk]

uhm... mg/gal? I deal in metric. mg/L

Using Magnesium Sulfate Heptahydrate, to reach 50mg/L, which is 50ppm, you need to add 0.51g/L.

.51 x 3.74 = 1.907g/gal, possibly round up to 2. I'm using 1.5 now.

I'll give it a shot, thanks!

 

[MisterBlah]

.51 x 3.74 = 1.907g/gal, possibly round up to 2. I'm using 1.5 now.

I'll give it a shot, thanks!

3.785 L/gal

Hardly a difference, I know.

It changes it to a whopping 1.93g/gal.

 

[ttystikk]

3.785 L/gal

Hardly a difference, I know.

It changes it to a whopping 1.93g/gal.

Doing it from memory, which is becoming increasingly imperfect. Running 2g/gal now, we'll see what we get.

 

[MisterBlah]

Doing it from memory, which is becoming increasingly imperfect. Running 2g/gal now, we'll see what we get.

Haha, yeah, I type 3.784 for the conversion just as often as I type 3.785. This is because if you go one significant figure farther, it's 3.7854.

 

[ttystikk]

Haha, yeah, I type 3.784 for the conversion just as often as I type 3.785. This is because if you go one significant figure farther, it's 3.7854.

Numbers geek! I know, takes one to know one...