K-lite fertilizer

All's square Mike. I agree completely - this is probably the best forum online for the sharing of info without all of the BS.

I agree completely about overfeeding. I've heard a number of "I never feed" stories myself.

Mussels notwithstanding, I am nervous about creating a deficiency, even if it's not the K itself. The fact that Rick has been successful with his blend is the only thing that encourages me to experiment.

Feedback Please

Email from Bill:


Hi Ray

This formula is mostly calcium nitrate and magnesium nitrate, with a little potassium phosphate and potassium nitrate. The micronutrient levels are the same (per ppm N) as the other orchid fertilizers.

The problem is going to be with the large amount of magnesium nitrate. Because it is very hydroscopic, this formula will get "wet" very quickly. I think that this formula may be a good candidate for a liquid formula. That way, you don't have to worry about its hydroscopic properties. I also think that we can get pretty close to the dry formula numbers (at least 7% N in the liquid form) because both calcium nitrate and magnesium nitrate are very soluble.

Aaron from GreenCare is on vacation this week, but I will talk to him about this when he gets back next Monday.


Fertilizer Formula
Total N 12.94%
NO3-N 12.38%
NH4-N 0.56%
Urea N 0.00%
P2O5 1.32%
K2O 1.30%
Ca 10.63%
Mg 3.61%
S 0.09%

B 0.0387%
Cu 0.0387%
Fe 0.1548%
Mn 0.0774%
Mo 0.0155%
Zn 0.0774%


At 125 ppm N, you get
120 ppm NO3-N
5 ppm NH4-N
5 ppm P (actual)
10 ppm K (actual)
100 ppm Ca
35 ppm Mg

1.50 ppm Fe (FeEDTA)
0.75 ppm Mn
0.75 ppm Zn
0.37 ppm Cu
0.37 ppm B
0.15 ppm Mo

Is this the formula that you want, or do you want to make any changes?

Thanks
Bill

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So this is basically a 13-1-1-11Ca-4Mg formula.

The liquid idea certainly removes the heterogeneity issue.

would it be able to be sent dry then water added to help reduce postage?
also, and i'm sorry if i missed this previously, but would this be a formula for r.o. water or tap/well water if the tap/well is 'decent'?

Ray said:

Email from Bill:


So this is basically a 13-1-1-11Ca-4Mg formula.

The liquid idea certainly removes the heterogeneity issue.

Click to expand...

That looks good.

If 1/2 of the Mg salt is Mag sulfate instead of Mag nitrate would that help staying in the dry?

I think we can afford to up the sulfate anyway. And it wouldn't bother me to drop the N a bit. (80-100?? rather than 125)

When the dry fertilizer becomes wet with absorbed moisture is there any degradation or change in the composition that would alter the nutrient values?

Would be great if someone could figure out how to package a fertilizer like this in "tea bags" that were individually sealed to keep out moisture. Then a person could just put one "tea bag" in a gallon of water, let steep then fertilize the plants with it.

there are pesticides that are marketed in dissolvable packets, usually for things that are going to be drenched or sprayed. the ingredients would have to be completely dry going in, though or the packets would all mush together

cnycharles said:

there are pesticides that are marketed in dissolvable packets, usually for things that are going to be drenched or sprayed. the ingredients would have to be completely dry going in, though or the packets would all mush together

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Yeah I have used those but I think it would not be possible to have the fertilizer dry enough to guarantee the bag would not dissolve from the inside out. If it could be packaged with the soluble plastic that would be a great retail item for a fertilizer company. Probably expensive tea bags but for us lazy people, that is what we need.

Ray said:

The problem is going to be with the large amount of magnesium nitrate. Because it is very hydroscopic, this formula will get "wet" very quickly. I think that this formula may be a good candidate for a liquid formula. That way, you don't have to worry about its hydroscopic properties. I also think that we can get pretty close to the dry formula numbers (at least 7% N in the liquid form) because both calcium nitrate and magnesium nitrate are very soluble.

Fertilizer Formula
Total N 12.94%
NO3-N 12.38%
NH4-N 0.56%
Urea N 0.00%
P2O5 1.32%
K2O 1.30%
Ca 10.63%
Mg 3.61%
S 0.09%

B 0.0387%
Cu 0.0387%
Fe 0.1548%
Mn 0.0774%
Mo 0.0155%
Zn 0.0774%


At 125 ppm N, you get
120 ppm NO3-N
5 ppm NH4-N
5 ppm P (actual)
10 ppm K (actual)
100 ppm Ca
35 ppm Mg

1.50 ppm Fe (FeEDTA)
0.75 ppm Mn
0.75 ppm Zn
0.37 ppm Cu
0.37 ppm B
0.15 ppm Mo

The liquid idea certainly removes the heterogeneity issue.[/B]

Click to expand...

To my mind the P and NH4 could be too low for certain growing conditions ( that was the issue for me and I think Wendy too with the MSU).

A part of the Magnesium must be applied as magnesium sulfate. Sulfate are indeed important for the plants. I tried an all mag nitrate formulation, no sulfate, and it performed not so well ( same for some TC media with only mag nitrate and no sulfate). From that, and the remaining, some people need to learn chemistry over there...

In a liquid formulation, it would precipitate a as kind of colloidal-looking stuff some hours after preparation, this is absolutely guaranteed. Insoluble compounds will form.

gonewild said:

When the dry fertilizer becomes wet with absorbed moisture is there any degradation or change in the composition that would alter the nutrient values?

Click to expand...

Massive degradation, the zinc, iron and manganese would be gone, and the calcium would blend with phosphate and sulfate to become insoluble. As a result, it would change everything...

likespaphs said:

would it be able to be sent dry then water added to help reduce postage?
also, and i'm sorry if i missed this previously, but would this be a formula for r.o. water or tap/well water if the tap/well is 'decent'?

Click to expand...

The problem is that once the bag is opened, it will suck in water like mad, so if I get it in for repackaging, it can become a sludge before anyone got it.

Rick said:

If 1/2 of the Mg salt is Mag sulfate instead of Mag nitrate would that help staying in the dry?

I think we can afford to up the sulfate anyway. And it wouldn't bother me to drop the N a bit. (80-100?? rather than 125)

Click to expand...

I'll ask about the mag sulfate.

ppm N is just a matter of final dilution.

gonewild said:

When the dry fertilizer becomes wet with absorbed moisture is there any degradation or change in the composition that would alter the nutrient values?

Click to expand...

Moisture doesn't degrade anything, but it does make it awfully difficult to measure!

Ray said:

I'll ask about the mag sulfate.

ppm N is just a matter of final dilution.

Click to expand...

Generally yes, but in this case some of the formula N is coming from the Mag nitrate. So if some of the Mag Nitrate is subbed with the sulfate salt, then that would change the ratios to N a bit (maybe a lot??), so at the same 1/2 tsp/gal instead of 125 N with respective ppms of all the other stuff, I wouldn't mind 80 to 100 ppm with everything else the same as previous.

Ray said:

Moisture doesn't degrade anything, but it does make it awfully difficult to measure!

Click to expand...

Mmmmh... Unfortunately in this case, moisture on a fertilizer creates a saturated solution, which reacts like hell, and will render insoluble whatever can be insoluble in the formulation. That's why I love to make my fertilizers myself when I can because there is no perfect solution.

Roth - so where are those metals going? Water makes them vanish into thin air?

Roth said:

To my mind the P and NH4 could be too low for certain growing conditions ( that was the issue for me and I think Wendy too with the MSU).

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Xavier, the ammonia/nitrate thing is strongly influenced by alkalinity (bicarbonate) concentration. The water you described as typical in your practice had pretty high (I think >100 mg/L) alkalinity (as well as high hardness). Much of the water in the great lakes region (or if you add a bunch of oyster shell or limestone fines to your potting mix like Wendy does) also produces high alkalinity conditions around the roots that is favorable for higher % ammonia use.

Most of us using the MSU type ferts are using RO, rainwater, or other very low alkalinity waters (with acidic-neutral potting mixes) which favors the high Nitrate % based ferts.

This is an area that I'm pretty sure we can't make a one fert fits all condition.

If my memory serves me, the MSU well water vs MSU pure water formulas not only had differences in Ca/Mg concentrations but also the % of ammonia vs nitrate to compensate for the generally increased alkalinity of many well waters.

Ray said:

Roth - so where are those metals going? Water makes them vanish into thin air?

Click to expand...

No, they become purely and completely insoluble as a fact... I made enough analysis of solutions, TC media, etc.. to know it, and it is basic chemistry.

Even the MS sold in powder by Sigma, when dissolved, prepared, and analyzed, does not have the same composition as a MS made directly from stock solutions.

When the moisture content of a powder increases, it makes a saturated solution, highly reactive. As a result, the Calcium replaces the iron in the EDTA ( it is even worse with EDDHA), and the free iron will react with phosphate, becomes insoluble. A part of the free iron will oxidize as rust, not too soluble either.

The calcium from the calcium nitrate mixed with a phosphate containing powder, when it starts to takes up moisture, will give calcium phosphate.

You can have a try, if you make the real solution from stocks, you get a crystal clear solution. If you use fertilizers, or mix the powders, wait a bit, you will see it becomes cloudy. This cloud is made of precipitates... In fact, the hydratation molecules of calcium nitrate, when it is in contact with phosphate salts, can be enough to make that precipitate.

You can try too to prepare the oligos solution of the MSU at a 1000x concentration in solution too, wait about a day or two, you will see the precipitate of iron ( and analysis confirmed a loss), most likely because of the boron in this case.

Rick, if I suggest to slightly increase the ammonium, it is to make the final fertilizer suitable for more types of water. I think at 125ppm total N, if about 20 comes from ammonium, that would be really fine...

Xavier, I cannot argue with a single point - but if the composition is made into a solution from the start, it is easier.

There is a lot of manipulation to be done to achieve what we're shooting for.

well, just like the msu stuff, there could be a rainwater and a hard water version

On a side note.....I've been using lowP/lowK for about 2 months now. I'm too wary to say yet that this is a direct result...as I said, I can maybe say after a year or 2, but at this moment in time, my paphs, especially, but not only, the ones under lights are doing very well. Leaves are hard and turgid, growth is good...and suddenly a whole bunch of plants are spiking, some far earlier in their growth cycle than expected...including 3 delanatii's (1 of them album), wardii- which only was in spike 4 months ago, and quite possibly topperi. I'll get back with a better opinion in a year......