The Cal-Mag of my dreams?

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Steve Johnson
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Re: The Cal-Mag of my dreams?

Post by Steve Johnson »

jerrytheplater wrote: Tue Feb 07, 2023 12:59 pmIf you are thinking that placing your probe in DI water that is covering the pumice for a few seconds while you take the reading will cause a problem, don't worry. It won't matter. It is soaking in DI water for prolonged periods that can ruin electrodes, like storing them for days. Rinsing with DI between readings to ensure you don't contaminate between multiple samples is perfectly fine. If you had to use tap water to rinse when you went between samples, you'd have problems of contamination of your samples.

Now I'm remembering a tip I read years ago when using Merck pH test strips. They said that some saturated KCl solution could be added to poorly buffered solutions to enable better pH readings-or something to that effect. That solution will have the pH of the DI water used to make it up. And it would probably be acidic due to dissolved CO2. But of such low strength that it would not affect pH readings in samples.

I didn't get out my book on rocks and minerals, but I remember there are different types of lava based on their pH reaction. Three maybe? Acid, neutral, basic. Also based on their flow characteristics. I have no idea if the solidified rock or pumice from those lava types have different pH reactions, but they could, and in my mind raise a doubt over assuming the pH of your pumice. This is why I press the issue.
Understood, and your first comment takes a load off my mind. The other problem with the pH 600 is that it won't read accurately in distilled water, but your tip on KCl solution will work -- I added an 8 oz. bottle of it from Apera Instruments to my Amazon shopping cart. I just want to make sure I'm doing this right:

1. Put 1 dry cup of pumice-granite gravel mix into my test jar.
2. Add 2 cups distilled water. Stir and let sit for an hour, then test the pH of the water.

I have a nice tall empty (and clean) coffee jar, so no problem dipping the meter into the water without having it accidentally contact the mix. How much KCl solution should I add to the water when I set up the test?
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jerrytheplater
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Re: The Cal-Mag of my dreams?

Post by jerrytheplater »

You don't even need to use that much pumice and water. I use a 200 ml plastic beaker. I fill 1/3 full with solid and add water to about 1/4" from the top. KCl solution, add about 5% by volume. Not much is needed. If you go with what you first said, just add a half ounce of KCl. Stir.

If you do see a pH change, let it sit a day and check again. Stir every once in a while.
Jerry Smith
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2012 USDA Hardiness Zone 6b: -5F to OF (-20C to -18C) min.
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Steve Johnson
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Re: The Cal-Mag of my dreams?

Post by Steve Johnson »

jerrytheplater wrote: Tue Feb 07, 2023 10:55 pm You don't even need to use that much pumice and water. I use a 200 ml plastic beaker. I fill 1/3 full with solid and add water to about 1/4" from the top. KCl solution, add about 5% by volume. Not much is needed. If you go with what you first said, just add a half ounce of KCl. Stir.

If you do see a pH change, let it sit a day and check again. Stir every once in a while.
Got it -- thanks for your help, Jerry!
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Re: The Cal-Mag of my dreams?

Post by jerrytheplater »

You're welcome.
Jerry Smith
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2012 USDA Hardiness Zone 6b: -5F to OF (-20C to -18C) min.
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Re: The Cal-Mag of my dreams?

Post by Minnesota »

Hello all--

I hesitate to even enter a conversation that's on the level of this one, but I'm curious as to your thoughts on a superficial level in regard to a fertilizer that seems to meet many of the qualifications you've been discussing. The label for this is, "Jack's Classic Tomato FeED," manufactured by JR Peters.

Please don't throw the tomatoes; words will suffice.

Bret
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Re: The Cal-Mag of my dreams?

Post by jerrytheplater »

I went to the JR Peters website to find more information on your fertilizer and did not find it. I was very disappointed. I was looking for a copy of the label and usage directions, along with what the fertilizer is derived from. https://www.jrpeters.com/online-store/T ... p184828904

I just sent them a message on their contact us form asking for that information.
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Re: The Cal-Mag of my dreams?

Post by Minnesota »

Thanks, Jerry. I'm very interested in the conversation, and there is a site listed that appears to be for the metals. http://www.aapfco.org/metals.html. One teaspoon per gallon of water each application/watering, or 1 tablespoon every 7-14 days. A page of analysis can be found here:

https://agr.wa.gov/departments/pesticid ... uct-lookup

I'd really appreciate the feedback.

Bret
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Re: The Cal-Mag of my dreams?

Post by MikeInOz »

Minnesota wrote: Mon Feb 13, 2023 5:07 pm Hello all--

I hesitate to even enter a conversation that's on the level of this one, but I'm curious as to your thoughts on a superficial level in regard to a fertilizer that seems to meet many of the qualifications you've been discussing. The label for this is, "Jack's Classic Tomato FeED," manufactured by JR Peters.

Please don't throw the tomatoes; words will suffice.

Bret
The P is unnecessarily high from what I see in google images.
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Re: The Cal-Mag of my dreams?

Post by BryanT »

I think this are the product certificates Bret was talking about.

From CDFA (California Department of Food and Agriculture):
CDFA Fertilizer Product Database.jpg
CDFA Fertilizer Product Database.jpg (120.29 KiB) Viewed 1062 times

From WSDA (Washington State Department of Agriculture):
Washington State Department of Agriculture.jpg
Washington State Department of Agriculture.jpg (64.18 KiB) Viewed 1062 times

Not sure why the different in each state's Total Nitrogen%.
Bryan
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Steve Johnson
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Re: The Cal-Mag of my dreams?

Post by Steve Johnson »

BryanT wrote: Mon Feb 13, 2023 11:05 pm I think this are the product certificates Bret was talking about.

From CDFA (California Department of Food and Agriculture):
CDFA Fertilizer Product Database.jpg

From WSDA (Washington State Department of Agriculture):
Washington State Department of Agriculture.jpg

Not sure why the different in each state's Total Nitrogen%.
Yeah, the CDFA's N reporting number makes no sense. I'm also not thrilled by the fact that WSDA is reporting total N without breaking it down into %NH4, %NO3, and %Urea if there's any urea in the fert. Maybe it doesn't matter because of this...

12% N available to the plant
15% P2O5 x .436 = 6.54% elemental P available to the plant
30% K2O x .83 = 24.9% elemental K available to the plant

If Jack's Classic Tomato Feed had 12% P2O5 (5.23% P), the NPK balance would be really good. But since the actual P is 1.3 times higher than it should be, I wouldn't recommend it for cacti or succulents. May not seem like much of a difference now, but figure on problems coming from the higher P in a few years. Generally speaking, cacti tend to be slow about complaining when they're getting too much or not enough of the nutrients they need for optimal growth over the years.
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Re: The Cal-Mag of my dreams?

Post by jerrytheplater »

Hey Bret. Thanks for that link. It is interesting as I just compared it to the label Peters sent to me. It is a pdf and I don't think I can post it here. The link includes Sulfur at 2.4% where the label does not. It also says the sample tested had 20 ppm Mo instead of the 9 ppm Mo the label guarantees. The concentration of Mo in the gallon of fertilizer would vary from 0.012 ppm Mo ( label min) to 0.026 ppm Mo (sample value). Not a significant difference. But it shows the tolerance they give themselves when formulating the fertilizer.

This fertilizer has a composition of 12% N, 15% P2O5 or 6.55% P, and 30% K2O or 24.9% K. Based on a ratio were the Nitrogen is fixed at 1%, you get a ratio of 1 N-0.6 P-2.1 K, which is close to what MikeinOz is suggesting or 1-0.4-1.5. If you use it at the label concentration of 1 tsp/gal, you will get about 160 ppm N in your fertilizer solution. The manufacturer says the fertilizer weighs about 5 grams per teaspoon.

To get about 50 ppm N in your fertilizer solution you would need to use about 1.6 grams of the dry fertilizer per gallon of water.

I would use this fertilizer at the 50 ppm N rate.

One thing to notice is the Potential Acidity is stated as 10 lbs CaCO3 Equivalent per ton. That means that spreading one ton of this fertilizer on an acre of land would change the soil pH to the same degree as spreading 10 lbs of limestone per acre. That means this fertilizer will have a neutral effect on the pH of the potting soil. It has a 3.4:1 Nitrate to Ammonium level. Which also tells you it is pretty neutral.
Jerry Smith
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Re: The Cal-Mag of my dreams?

Post by Minnesota »

THANK YOU ALL for weighing in on this. I really appreciate your feedback and suggestions. Now, I'll take some moments to reread and digest the information and to formulate a plan going forward--and continue to eavesdrop on the chemistry lesson you guys are having!

Mike--gotcha.
Bryan--thanks for weighing in with the page support.
Steve--I knew you'd look at the nitrogen, and that's one of the reasons your input was needed.
Jerry--thank you for the calculations and the pH work. Initially, I had already added crushed limestone to my planting mix, and this will affect the forward actions, I believe.

Muchas gracias!
Bret
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Re: The Cal-Mag of my dreams?

Post by Steve Johnson »

jerrytheplater wrote: Tue Feb 14, 2023 12:34 amThis fertilizer has a composition of 12% N, 15% P2O5 or 6.55% P, and 30% K2O or 24.9% K. Based on a ratio were the Nitrogen is fixed at 1%, you get a ratio of 1 N-0.6 P-2.1 K, which is close to what MikeinOz is suggesting or 1-0.4-1.5.
Sorry, but I have to agree with Mike -- the P is unnecessarily high. Of course that's easy to say without proof of what abnormal growth from higher P looks like on cacti. Which brings up something that irks me to no end...

A number of years ago, I saw a very interesting article online from a noted cactus expert discussing the dangers of overfeeding. His article included photographic examples of abnormal stem growth on cacti caused by overfeeding, with descriptions of what the abnormalities were. Can't remember the author, can't remember the online source, and trying to find it with keyword searches on DuckDuckGo, Google, etc. was a waste of time. If anyone here remembers the article and can find it for us, that would be great. I'm pretty sure the author included details on the fertilizers he discussed, and if he did, I'd be taking a very close look at the NPK values in his article.

In the meantime, here's a question for Mike -- when it comes to P in the proper NPK balance, is not enough better than too much?
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Re: The Cal-Mag of my dreams?

Post by jerrytheplater »

Steve, overfeeding with what? That is a big question to answer. Is it N alone, or P, or K? Is it the proportion of the major nutrients to one another? If you find your article I will be very interested in seeing what is meant by overfeeding.

I'd like to see some references that show what the effects of over feeding with P causes. Do you happen to know of any? I need to go over those articles I posted up last week. Might be something in there.
Jerry Smith
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2012 USDA Hardiness Zone 6b: -5F to OF (-20C to -18C) min.
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Re: The Cal-Mag of my dreams?

Post by Steve Johnson »

jerrytheplater wrote: Tue Feb 14, 2023 4:46 am Steve, overfeeding with what? That is a big question to answer. Is it N alone, or P, or K? Is it the proportion of the major nutrients to one another? If you find your article I will be very interested in seeing what is meant by overfeeding.

I'd like to see some references that show what the effects of over feeding with P causes. Do you happen to know of any? I need to go over those articles I posted up last week. Might be something in there.
What irks me the most is that I didn't archive the article on my computer when I had a chance. Didn't seem all that important at the time, long before Mike came on the CactiGuide scene. Now it is -- and I can't find it anywhere! ](*,) One source I can point to comes from something he posted in August 2020:
MikeInOz wrote: Sat Aug 22, 2020 3:08 amBelow is the ratio of these elements found in leaves/(succulent stems) and flowers...

NPK_chart.JPG
NPK_chart.JPG (16 KiB) Viewed 1012 times
We can go even further -- quoted from my Fertilizers Explained thread:
SDK1 wrote: Wed Feb 01, 2023 3:55 pm Steve,

Thanks for the links but I'm afraid I still don't see where the "1.0 : 0.4 : 1.1-1.7" value is originating from. Since this ratio is what all of the discussions about ferts and pH are built upon, I'm very curious what the source of the ideal ratio for NPK is.

Mike,

Thanks for that, could you share the title and author of the book?
MikeInOz wrote: Wed Feb 01, 2023 11:45 pm
SDK1 wrote: Wed Feb 01, 2023 3:55 pm
Mike,

Thanks for that, could you share the title and author of the book?
''Growing Media for ornamental plants and turf''
K.A. Handreck and N.D. Black
University of NSW press.
SDK1 wrote: Thu Feb 02, 2023 2:34 amPark S. Nobel has done a lot of great research over the years with cacti/succulents and a few of their papers aren't paywalled anymore.

The first is one of my earliest finds. I find the tissue analysis tables quite helpful/interesting and I think the values line up rather well with your assessment of 1:0.4:1.1-1.7. (Edit: I generally follow the idea that it's best to supply nutrients in the amount they're being used by the plant and tissue analysis of the plant is how that's derived) I also find the rather strong negative reaction of cacti to Na rather interesting, seems they're more sensitive than leafy plants even. The PDF download is at the bottom of the page.

- <BOGUS PAYWALL>https://bsapubs.onlinelibrary.wiley.com ... .tb12473.x <paywalls are the devil, the authors don't even see any money from them>

Non-paywalled link: https://www.eeb.ucla.edu/Faculty/Nobel/ ... 20Ecol.pdf
Using N as a constant of 1, it appears that the acceptable P range for cacti is 0.17-0.4. If P is higher, it could force them to grow beyond their natural limits. How much higher before it causes problems? That's a question I can't answer. And what are the problems? My instinctive guesses are A. weak root growth, B. stems that look abnormal compared to type for the species, and C. failure to flower normally or flower at all. "Stems that look abnormal compared to type for the species" -- the article I can't find would've given us comparisons. With that said, I would caution against confusing abnormal with unusual -- cacti reaching their genetic growth potential under cultivation will generally look bigger and healthier than their counterparts fending for themselves in the wild. For people who are used to seeing cacti being grown hard, anything else will look unusual, not abnormal as long as those cacti are being grown well.
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