Rick: ammonia is also measured by the Kjeldahl method, we measure nitrate (by difference) before and after its conversion in ammonia after its reduction. Urea alone is measured after its hydrolyse (in ammonia) by .... urease.
K-Lite Update?
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Rick: ammonia is also measured by the Kjeldahl method, we measure nitrate (by difference) before and after its conversion in ammonia after its reduction. Urea alone is measured after its hydrolyse (in ammonia) by .... urease.
Rick
Well-Known Member
Thanks for the correction Brabantia
In my lab we measure ammonia by Nesslers, salasilic acid, or ion specific probe methods. Nitrate by cadmium reduction method. Since I need those constituents specifically (for toxicity reasons), TKN doesn't directly separate the ammonia from all the other "bio available" forms of N. Our waste water engineers like to get TKN to measure "total bug food" N for activated sludge plants, but that doesn't help me to measure individual toxic ammonia or nitrate concentrations for fish lethality issues.
TKN also seems to be a cumbersome method that our limited lab equipment does not have capabilities to handle. Maybe HACH has a new test out now, but TKN is a test we generally send out to a more complete analytical lab.
Rick
Well-Known Member
Rick
Well-Known Member
Jack
Most of the time when a nutrient is not specified (like N, P, or K), ppm is inferred as the TDS or total dissolved solids concentrations of your complete fertilizer mix.
This can be measured at home with a TDS meter. Actually this is just measuring the conductance of the salts in solution as a surrogate for the actual dissolved solids concentration.
If you got the most recent edition of Orchids magazine, Holger Perner has a nice write up on this.
Most of the time when a nutrient is not specified (like N, P, or K), ppm is inferred as the TDS or total dissolved solids concentrations of your complete fertilizer mix.
This can be measured at home with a TDS meter. Actually this is just measuring the conductance of the salts in solution as a surrogate for the actual dissolved solids concentration.
If you got the most recent edition of Orchids magazine, Holger Perner has a nice write up on this.
newbud
Orchid Maniac
Ok...thanks for all your help Rick and Brabantia. This is all a little above my head but get the gist of it.
Mocchaccino
Biomedical Scientist
I have recently made my K-lite and would like to seek opinion from Ray and Rick.
Here's the analysis of my local water supply (which is so SOFT):
In average,
pH = 8.5
Conductivity at 25 degrees = 154 uS/cm
Total alkalinity (as CaCO3) = 23 mg/L (ppm)
Total hardness (as CaCO3) = 38 mg/L (ppm)
Calcium = 13 mg/L (ppm)
Magnesium = 1.5 mg/L (ppm)
I have a fertilizer which is 20-20-20 (Nitrogen in mixture of urea and ammounium salts; P2O5, K2O) and it contains micronutrients but undefined. I read abax's thread and took it as a reference. I calculated and finalized the mixture in the following proportions: (I don't have CaNO3 in hands so I am just going to substitute with CaCO3)
For 1 Litre of water:
0.33 g 20-20-20 fertilizer + 0.33 g CaCO3 + 0.33g MgSO4 (Epsom)
which is equivalent to (per gallon):
1/8 tsp 20-20-20 fertilizer + 1/8 tsp CaCO3 + 1/8 tsp MgSO4 (Epsom)
The N:K ratio is not up even to 10:1. Should I increase the N?
Here's the analysis of my local water supply (which is so SOFT):
In average,
pH = 8.5
Conductivity at 25 degrees = 154 uS/cm
Total alkalinity (as CaCO3) = 23 mg/L (ppm)
Total hardness (as CaCO3) = 38 mg/L (ppm)
Calcium = 13 mg/L (ppm)
Magnesium = 1.5 mg/L (ppm)
I have a fertilizer which is 20-20-20 (Nitrogen in mixture of urea and ammounium salts; P2O5, K2O) and it contains micronutrients but undefined. I read abax's thread and took it as a reference. I calculated and finalized the mixture in the following proportions: (I don't have CaNO3 in hands so I am just going to substitute with CaCO3)
For 1 Litre of water:
0.33 g 20-20-20 fertilizer + 0.33 g CaCO3 + 0.33g MgSO4 (Epsom)
which is equivalent to (per gallon):
1/8 tsp 20-20-20 fertilizer + 1/8 tsp CaCO3 + 1/8 tsp MgSO4 (Epsom)
The N:K ratio is not up even to 10:1. Should I increase the N?
Rick
Well-Known Member
I'm not sure if this is going to cut it for you Mocchacino.
The use of calcium nitrate was not only to get the Ca up, but to replace the nitrogen lost when reducing your 20-20-20.
Also calcium carbonate (limestone) is pretty insoluble in the short term until you get to a pH of about 2. At a pH that is safe for plants it will probably take weeks or months to dissolve.
Also with soft water you also have low alkalinity. This is a better environment for the use of nitrates as your nitrogen source instead of urea and ammonia.
So by cutting down the use of your 20-20-20, you have reduced K relative to Ca Mg (good), but also cut down the amount of N relative to Ca an Mg (probably not so good).
However, given that I know some growers that don't feed at all, and irrigate with hard water (that get good results) you are somewhat replicating what they do, and it may work out just fine.
I am a bit concerned that by using relatively insoluble calcium carbonate, with very soluble mag sulfate, that you could end up reversing the ratio of Ca to Mg that the plants see (which will also not go well for you).
The use of calcium nitrate was not only to get the Ca up, but to replace the nitrogen lost when reducing your 20-20-20.
Also calcium carbonate (limestone) is pretty insoluble in the short term until you get to a pH of about 2. At a pH that is safe for plants it will probably take weeks or months to dissolve.
Also with soft water you also have low alkalinity. This is a better environment for the use of nitrates as your nitrogen source instead of urea and ammonia.
So by cutting down the use of your 20-20-20, you have reduced K relative to Ca Mg (good), but also cut down the amount of N relative to Ca an Mg (probably not so good).
However, given that I know some growers that don't feed at all, and irrigate with hard water (that get good results) you are somewhat replicating what they do, and it may work out just fine.
I am a bit concerned that by using relatively insoluble calcium carbonate, with very soluble mag sulfate, that you could end up reversing the ratio of Ca to Mg that the plants see (which will also not go well for you).
Mocchaccino
Biomedical Scientist
Thanks Rick!
I may then have to seek a bottle of CaNO3 for use. For the time being I then heavily reduce the Mg portion in order that the Mg wont exceed Ca.
I may then have to seek a bottle of CaNO3 for use. For the time being I then heavily reduce the Mg portion in order that the Mg wont exceed Ca.
Mocchaccino, if you'd like to try the K-Lite, I'd be happy to
send you a jar from Ray's website. It's sooo much easier
than trying to mix and balance. If you'll PM your mailing
address to me, I'll be glad to do it.
My name is Angela btw.
send you a jar from Ray's website. It's sooo much easier
than trying to mix and balance. If you'll PM your mailing
address to me, I'll be glad to do it.
My name is Angela btw.
Mocchaccino
Biomedical Scientist
Thanks Angela!~ But I am living far beyond your place. I would like to try mixing my own before owning others. It seems a lot fun to me
I just got my first package of K-Lite, and I have a couple of questions.
First, I mix my fertilizer in a 5 gallon bucket. I use RO water. Should I use one tsp. per gallon of water? I am assuming that the end result would be 150 ppm N? Is that correct?
2nd, do I still need to add oyster shell for calcium, or is there enough in the K-Lite?
I have been doing my own version of K-lite and and have seen some good results.
First, I mix my fertilizer in a 5 gallon bucket. I use RO water. Should I use one tsp. per gallon of water? I am assuming that the end result would be 150 ppm N? Is that correct?
2nd, do I still need to add oyster shell for calcium, or is there enough in the K-Lite?
I have been doing my own version of K-lite and and have seen some good results.
I began using K-Lite at half a tsp., but since we're moving
into fall in Ky, I've cut back to 1/4 tsp. per gallon in my
Spot Shot. I've never used RO and can't address that
question. My theory is to go lightly when switching fertilizers until you see exactly how it affects your plants.
into fall in Ky, I've cut back to 1/4 tsp. per gallon in my
Spot Shot. I've never used RO and can't address that
question. My theory is to go lightly when switching fertilizers until you see exactly how it affects your plants.
I think it depends on how accurate you are trying to be. After conferring a bit with Ray, I make a 10% stock solution by putting 50 grams of the granular mix in a contained and adding RO until the weight is 500 grams (ends up being very close to 500 mL total solution). Obviously, this requires a scale, but I like the precision.
I keep this stock solution refrigerated between use and it stays crystal clear this way with no precipitation or particulate matter. 20 mL of the stock in 1 gallon of RO creates a 65 ppm N solution that I use with every watering.
I keep this stock solution refrigerated between use and it stays crystal clear this way with no precipitation or particulate matter. 20 mL of the stock in 1 gallon of RO creates a 65 ppm N solution that I use with every watering.
K
keithrs
Guest
I use 35 ppm n every watering from a stock. I'm sure Ray would be more then happy to direct you on what to do.
E
Eric Muehlbauer
Guest
I use 1 tsp/gal for vandas, catts, phrag hybrids, and strap-leaf paphs. I use 1/2 tspn/gal for the rest of my paphs, besseae and schlimii, neos and bulbos. Once/week now, later it will be every 2-4 weeks (depending on temperature and winter light levels), with none at all for the cooler growing species paphs. The underlights plants will get fertilized at the same rates, but every other watering.
