I think I remember seeing 114ppm N for full strength Foliage Pro.

Josh

The fertilizers I mostly use are JR Peters or Jacks Brand. I haven't used Foliage Pro, so not much experience with growth results. I do like the higher nitrate nitrogen listed in the formulation. As far as nutrient ratios, I go for more Potassium about 1.5 times more than the 3-1-2 ratio. From the charts of nutrients removed by crops, it shows more potassium than N removed. I am not sure if tissue samples are only leaf and stem. Tomatoes seem to be heavy Potassium users. I am testing Jacks Petunia Blend Fertilizer at 20-6-22 with 5.3%Nitrate N. I like the Potassium source from Potassium Nitrate or Potassium Sulphate , rather than Potassium Chloride used in cheaper blends.

Addition: At 1tsp/Gallon 9%N the solution is about (5ml)*.09/3785= 119ppm N. This approx to Josh's Post.

Can't help on the meter reading, but your calculation was interesting.

The 40 ppm N sounded kind of low (recall some people here posting they fertigate at 100ppm N) but when googled found at the manufacturer's website a testimonial claiming Foliage Pro "application rates of 50 to 100 ppm N produce better growth than bagged dry fertilizers at 200 to 400 ppm N." (Have to presume it's not being compared to a higher N fertilizer program which lacks micros.) So maybe 40 ppm is right.

Since it is different from numbers above, just how did you do your calculations?

dale92539, Thanks for commenting, and posting the useful conversion and TDS information.

Not sure I'd have been comfortable with the assumptions behind the "total" ppm approximation, but can't argue the result is not in the ballpark of the reading (especially since 640 is said to come closer to "reality" for the complex mix of ions in fertilizer solutions).

And thanks for the discussion of of greenman's (thanks) number. So it looks like the only difference is the assumption of specific gravity - 5g/tsp or (my) 6.6 g/tsp.

acg85 - guess we were posting at almost the same time.

>how did you do your calculations

lot's of ways to get to mg/L (which is ppm)

from the label 1247gm and 32 fl oz, so 1247g/946ml, or 1.32gm/ml

1/4 tsp is 1.25 ml, and so is 1.65g
9% of that weight is N = 0.149g = 149mg
1 gal = 3.785L, so 149mg/3.785L = 39.4 mg/L = 39.4 ppm N

for K elemental: 6% = 99mg, and K is 83% of "K2O" weight = 82 mg = 22 mg/L = 22 ppm

(oh, if you assumed 1 gm/ml the calculated ppm N would be a bit under 30 same as the 119 (1 tsp) calc in dale's 2nd post. )

I see. Whenever I google this kind of numbers stuff, it seems 99% of results are from "medicinal" growing forums. Maybe try searching there or if you post on one of them, someone will probably give you the Foliage Pro numbers from their meter.

I not sure the solutions need to be very high accuracy. I used the definition of 1ppm as 1mg/Liter. (1ppm= 1gE-6grams * 1000 grams of water). Or 1 million parts water to 1 part nutrient by weight. This is referenced to Sp=1 (1Kg per Liter). I am not sure if the total solution weight is being truncated , because the error is so small. The Percentage was treated as Parts per Hundred, rather than % of the total solution weight. I think the Sp you referenced, just includes the weight of all the nutrients plus the water. Just depends on how concentrations are being defined. The conversion Factors can be from 500 to 750 ppm per ms. The EC is the constant between meters, just the displayed or estimated TDS will vary. Also the accuracy of the tsp's used etc. If you multiply your EC reading in us(330) by 0. 5 to 0.75 this would give the PPM range of 165ppm to 247.5ppm. If you know the EC you want to stick with this would be accurate. Second mathematically estimating the mass of nutrients per Liter or Gallon of solution

Addition: If the 1.32g/ml is accurate, That means 320 grams of mass per liter of water in the solution. Weight to Weight ratio is Nutrient mass/litre of solution mass or 320g/1320g or about 24.2% total solids.

Edit: Sometimes the Actual Nutrients are higher than label, They lower values sometimes to be safe with labeling laws.

Sidenote: Also most salt based soluble fertilizers such as MG All Purpose are listed as Sp=0.8 or 0.8g/ml

> I not sure the solutions need to be very high accuracy.
Absolutely agree. It was more curiosity about label analysis numbers themselves, than anything else.

Even in the most complex hydro, seems it'd be best to just find an EC/ppm range with your meter that works for your nutrients, phase of growth, and application, and stick with it. And most relevant to this sub-forum - probably even less important for container culture - especially with fertigation/flushing.

acg, that was an interesting idea. Looks like they use, and post numbers about, DG Grow and Bloom rather than FP. But they consistently post they use lower EC/ppm of Dyna-Gro than of other fertilizer brands.

Serial dilutions (unfortunately without good volumetric apparatus) of FP as read on my el-cheapo meter actually plotted pretty linearly in the useful range, but since that wouldn't tell if the factory calibration was correct, if concerned, I should probably buy a standard.

Probably just feeling overly-frugal because I used to have access to a lab where it would have been trivial to make an appropriate KCl solution for pennies. Anyway, checking into the history of the conductivity standards turned out kind of interesting (in a geeky way). Not a chemist, but thought my chem history was decent, and was surprised I had never heard of a demal, or of the controversy between a liter and a cubic-decimeter. At least it now seems sensible that a common standard is an uncommon number like 1413 µS/cm. But I'm still not sure how to pronounce "mho" :)

Pronounced as "Moe" in the three stooges, Ohm spelled backwards for conductance instead of resistance. It sounds like you have had more experience in chemistry. You are probably are more familiar with the correlation of EC to TDS calculations than myself. I am more of a Electronics background. To my Knowledge the EC is the reciprocal of the resistance of a cubic cm of solution for (s/cm or mho/cm). Measured with a low Frequency AC voltage to prevent polarization of the electrodes. 1 mho is 1 ampere of current (1 coulomb of charge/sec) per volt of potential difference on the electrodes. The value of 1 milli-siemem or 1 millimho of Conductance is equivalent to 1 Kilo Ohm of resistance.

I confirmed my EC meter by measuring a hydroponics fertilizer that provides EC numbers. Tap water will influence the numbers, so fertilizing should be based on the final mixed solution. We have good tap water locally, so I only use distilled for cleaning my meter probes.

My target has been 0.6, which seems to have had good results with my plants.

Honestly though, the most reliable method is checking the EC of a known solution. You can get some fairly cheap online or at hydroponics stores. It's the recommended method, even with expensive meters.

Dale has very good advice about checking you meter conversion factor, that was the first thing I did when I got my meter.

Don't forget to check if your meter is temperature compensating (greatly preferred), as that also can affect your readings.

Math Error in First Post added Correction. The TDS in Foliage Pro Solution must be much higher than approximated.

Edit: Math Error

1tsp= 4.94 ml 4.94grams at sp=1

1US Gal = 3.785411784 liters

(0.18)*(4.94g/4)/3785= 235ppm Error

Should be

(0.18)*(4.94g/4)/3785= 58.7ppm

at conversion factors of 500 ppm/mS or 640 ppm/mS

58.7ppm/500= 117uS or 58.7ppm/640= 91.7uS

Too Low to be accurate

"Edit: Math Error

1tsp= 4.94 ml 4.94grams at sp=1

1US Gal = 3.785411784 liters

(0.18)*(4.94g/4)/3785= 235ppm

Should be

(0.18)*(4.94g/4)/3785= 58.7ppm

at conversion factors of 500 ppm/ms or 640 ppm/ms

58.7ppm/500= 117uS or 58.7ppm/640= 91.7uS

Too Low to be accurate

"Not sure I'd have been comfortable with the assumptions behind the "total" ppm approximation"

You were Correct on that

Maybe others that use Foliage Pro can validate the EC readings with other meters.
Even at 320 grams/Liter 1/4 tsp/Gal gives only about 105ppm total concentration. This is about 164 uS at 640 factor.

MSDS Sheet for Foliage Pro ,listed density 13.3g/cubic cm. Probably mean 1.33g/cu cm. List solids content at 43.2%.

http://www.dyna-gro.com/Website%20pdf%20Files/SDS_DG_Nutrients;_Grow_Bloom_Pro_Formulas.pdf

Addition: Because of the wide variance of PPM estimates, I don't use EC for nutrient solutions. EC is good to check general salt levels in Growing Medium. I like your idea of creating of a standard Potassium Chloride calibration solution. Maybe very sensitive Scales or Hydrometer is useful for density checking. Some Saltwater aquarium supplies include test instruments.

EC Readings for reference of Different Formulations based on PPM Nitrogen desired.

The 16-4-12 (4-1-3) is closest to the 3-1-2 ratio of Foliage Pro.

Another Good EC Table Reference

dale, thanks; you always find great charts and graphics.

PS Was able to obtain a commercial (HM) KCl standard rated at 2000µS @25˚C. I was pretty satisfied with the resulting consistent readings of ~2048µS at room temp, as the (cheap) meter's specs claimed +/- 2%. (So close, did not feel the need to adjust the factory calibration.)

Peters or Jacks provide info. I think Dyna Gro dropped the ball on this. I couldn't find much info from them. It may be out there, just did not find it. The 330uS or 0.33mS looks petty close with the 50ppm N stated at 0.32mS

Sidenote: I wanted a better EC meter for in Pot Readings. Mainly for data on Fertilizer Release rates on Organics and CRF's ,also noting temps. There is to much speculation about organics. I will have good data for reference either way it goes. Just reading reports and opinions is one thing, but actual personal empirical data is another.

This might be helpful. At least I hope it works.

Al

Al, thank you for contributing the downloadable NPK-ppm calculator. The tiny .html file should open up in any web browser (and do the math as long as javascript is enabled). Looks like it presumes 1 gm/ml, and uses label numbers to give ppm of N, and "elemental" P and K, or to give a volume for a target N.

dale, sounds like quite a side-project, but see how you'd have no other easier way to attempt to quantify their effects in your unique growing situations. I'm sure we'll be in for some interesting posts.

Can someone tell me if Foliage Pro can be used in raised beds and container gardening for growing veggies?

If it matters, I am in No. VA area which is outside of DC metro area.

Mindy

It can be used for containers & RBs, but slow release (not controlled release) fertilizers are less expensive and probably a better choice for growing in the ground. Too, there's the fact that the best fertilizer program for gardens and beds will be the one that follows the recommendations accompanying a soil test.

Al