added calcium?

[fanaticactus]

For years I've been wondering about those cacti whose cultural suggestions claim they grow in limestone outcroppings or they prefer some calcium added to their soil. In my current soil mixes I do not add anything, as I'm afraid of using the wrong supplements. For 'added calcium' I tend to think that crushed eggshells would supply the desired trace of calcium. I'm afraid that horticultural limestone would be too strong. Does anyone supply lime or calcium to their mix when dealing with cacti who prefer it? If so, what is a preferred source? Or doesn't anyone bother with this particular detail?

[One Windowsill]

Does your fertiliser contain calcium?

[Steve Johnson]

For years I've been wondering about those cacti whose cultural suggestions claim they grow in limestone outcroppings or they prefer some calcium added to their soil. In my current soil mixes I do not add anything, as I'm afraid of using the wrong supplements. For 'added calcium' I tend to think that crushed eggshells would supply the desired trace of calcium. I'm afraid that horticultural limestone would be too strong. Does anyone supply lime or calcium to their mix when dealing with cacti who prefer it? If so, what is a preferred source? Or doesn't anyone bother with this particular detail?

I learned a lot about fertilizers from MikeInOz when he joined the forum last summer, and this was a revelation...

It's not just about Calcium, but also having a good balance between Calcium and Magnesium. He recommended that the Ca-to-Mg ratio should be 4:1. Take a look at the chemical analysis of the Dyna Gro All-Pro 7-7-7 I've been using for over 9 years:



My cacti are getting enough Ca from the 7-7-7, and the Ca-to-Mg ratio is perfect. IMO these are good numbers to aim for with whatever fert you're using. Mike stated somewhere else that there's no such thing as too much Ca -- since he's a trained horticulturalist with a good number of years successfully growing cacti, maybe he'll chime in with some advice for you. If you decide to use a Ca supplement, the only advice I can offer is to make sure that it includes Mg to strike the 4:1 balance. You might want to check out the Cal-Mag plant supplements on Amazon and look at what's on the label. From the cursory glance I made, the ones I saw are 1-0-0 with a Ca-to-Mg ratio of 3.33:1. Not ideal, but perhaps that would be acceptable, although I don't know if adding N to the N in your primary fert would be a problem.

As far as I'm concerned, Dyna Gro ferts are the "gold standard" here in the US. With that said, a gallon of 7-7-7 is the only quantity available, which makes it expensive. Orchid Pro 7-8-6 is the next best thing, available in smaller and more affordable quantities. Here's the chemical analysis:



I've been supplementing my 7-7-7 with Potassium sulfate, and we can do the same thing with the 7-8-6. If this is something you'd like to pursue, I'll be happy to give you some guidance.

[fanaticactus]

This is good, Steve...in more ways than one. I also have some Dyna-Gro...the orchid formula...because of the smaller size available. I would be curious about added potassium sulfate. Liquid or powder? How much? etc. Thanks, buddy!

[Steve Johnson]

This is good, Steve...in more ways than one. I also have some Dyna-Gro...the orchid formula...because of the smaller size available. I would be curious about added potassium sulfate. Liquid or powder? How much? etc. Thanks, buddy!

You're welcome, my friend!

The Potassium sulfate I use is 0-0-52 coming in powder form. You can buy it in 3.5 oz. plastic resealable bags on eBay here:

https://www.ebay.com/itm/283493623862?h ... SwAbxebYaY

I dilute my Dyna Gro 7-7-7 at half-strength (1/2 tsp. per gallon of water). If you're going with half-strength as well, you'll supplement the 7-8-6 with 1/8 tsp. Potassium sulfate. If you're going with full-strength, simply double it. Here are the steps, assuming that your dilution is half-strength:

• Pour the 1/2 tsp. of Dyna Gro into an empty gallon jug, and fill the jug up to the fill line with water.

• Pour some of the watering solution into a jar, and add 1/8 level (not heaping) tsp. of Potassium sulfate. As I came to find out when I started using it, the powder doesn't dissolve instantly, so stir the water around with a spoon until it's thoroughly dissolved, then dump the solution back into the jug.

Shake well, and water away. This is pretty easy, but there's a more precise way to go about it...

The problem with dry measurement is the fact that 1/8 tsp. of Potassium sulfate powder includes teeny-tiny airspaces, so the solid part is a bit less than 1/8 tsp. If you're willing to go far enough for the kind of precision I deal in (I've been in the precision business for about 34 years), here's what to do:

• You'll need a digital scale that reads in kilograms/grams. (Reading down to 10ths of a gram is great, but not required.) If you have one, go to step 2.

• Fill an empty gallon jug with distilled water or rainwater, not tap or well water.

• Fire up the scale, put a piece of paper on the scale, and add 8 grams of Potassium sulfate. If your scale reads in 10ths, make it 8.2 grams.

• Dump the powder into the gallon of water and let it dissolve thoroughly. You now have a gallon of Potassium sulfate stock solution.

• Prepare the watering solution by pouring 5 fluid ounces of stock solution into an empty gallon jug, add 1/2 tsp. of the Dyna Gro, and fill the jug with water up to the fill line.

Shake well, and water away.

As a microscope field service and calibration technician, precision has been the name of my game. Do we need to be all that precise? Maybe not, but for those of us who don't mind going through the procedure I just described, it's not that much trouble -- and our cacti might be the better for it over the years. (I actually enjoy this kinda stuff anyway, but then again I'm weird! ) By the way, thanks go to Jerry Smith (jerrytheplater) for calculating the precise amount of Potassium sulfate going into the stock solution we'll use with the Dyna Gro 7-7-7 and 7-8-6 ferts.

[keith]

As a microscope field service and calibration technician' Microscopes like for electronics ?

[Steve Johnson]

As a microscope field service and calibration technician' Microscopes like for electronics ?

The company I work for services microscopes in all fields that use them -- industrial (including microelectronics), healthcare (doctors, hospitals, etc.), and various research facilities. On the industrial side, we calibrate different types of measuring systems for microscopes. Not many people know how to do what I do, so it's nice to be in demand with a rather specialized skill set.

[keith]

We use them in electronics. And my trusty Eye loupe 4X

[Steve Johnson]

We use them in electronics. And my trusty Eye loupe 4X

The outfit I work for is a company called McBain Systems (founded as McBain Instruments in 1965), our headquarters are currently in Westlake Village. Chances are that a McBain field service tech has serviced your scopes. Not me, though -- my territories are mostly in El Segundo/South Bay/Long Beach.

I have an old B&L 10X eyepiece in my tool case -- flip it over, and it makes a great loupe. I use it to look at my cacti up close, so there are lots of fascinating things I wouldn't see with the bare-nekked eye. Not much of a stretch to go from that to buying macro lenses for my DSLR camera. They aren't as expensive as they used to be -- on my to-do list.

[jerrytheplater]

Since you are talking about microscopes, here's a photo I took of some aquatic algae using an American Optical Spencer Binocular Microscope. I held a digital point and shoot up to the eyepiece and took a photo. No adapter, hand held. I love that microscope.

Staghorn (Large).JPG (67.4 KiB) Viewed 2496 times

[keith]

The outfit I work for is a company called McBain Systems (founded as McBain Instruments in 1965), our headquarters are currently in Westlake Village. Chances are that a McBain field service tech has serviced your scopes. '

oh yea we know McBain and my companies in Westlake Village not that I show up there much anymore .

[Steve Johnson]

By the way, Jerry was able to correct me on what I should recommend for the Potassium sulfate stock solution supplementing the Dyna Gro 7-8-6...

7 grams 0-0-52 Potassium sulfate per gallon of water is the same stock solution I use, the only difference is that you'll put 7 fluid ounces of it along with 1/2 tsp. of 7-8-6 into a gallon of watering solution.

Thanks for the correction, Jerry!

[samreu]

Looking for some help from you guys so I can simplify adding K2SO4 to my DynaGro 7-8-6 with the addition of the dry product rather than making a "stock solution". I am a little confused and maybe not catching on. Above, Steve suggested 1/8 tsp of the powdered/dry K2SO4 to 1 gallon of the Dyna Gro mixed solution. Under that calculation, 1 ounce (28gm) of K2SO4 ( around 2 tsp from conversion sheets I have seen/used) would give me 16 gallons of enhanced K2SO4/Dyna Gro ready-to-use. Under the stock solution/pre-mix with water and the suggestion of 7-8 grams per gallon of water to make K2SO4 stock, 1 ounce would make roughly 4 gallons of "stock solution". At 128 ounces/Gallon, 1 gallon of stock solution would yield roughly 18 gallons of ready-to-use enhanced K2SO4/Dyna Gro at the prescribed 7 ounces of "stock solution" per gallon of Dyna-Gro solution. My 4 gallons of stock solution from my ounce of K2SO4 would then yield 72 gallons of ready to use enhanced K2SO4/Dyna Gro mix versus the dry scenario that only yields 16 gallons? Unless the weight/volume calculator I used is way off, something doesn't jive? The dry ratio has to be much lower???

https://www.aqua-calc.com/calculate/weight-to-volume

[jerrytheplater]

I sent a correction to Steve because initially his recommendation was to add way too much K2SO4. I sent him the correction and calculations. Steve has rounded the calculations a bit, but the plants don't mind. I did not check your link, but you have to remember that when using volumes of ground chemicals rather than weight, you get all kinds of errors due to particle size, density of packing of the particles.... I weighed out one level tsp 10 times and took the average of the weight and got about 7 grams per tsp if not packed down. I got about 7.5 gram per teaspoon if I tapped it down. I used my lab scale at work which measures to 0.001 gm accurately. See if this helps:

The purpose of the stock solution is to enable the user to add a small amount of K2SO4 to the gallon of fertilizer being mixed up. The stock solution is made by adding 7 grams of K2SO4 to one gallon of water. (Best if it is rain water, or RO, or DI, or distilled). Mix the gallon to dissolve the K2SO4. [7 gms K2SO4/128 ounces in the stock solution = 0.055 gm K2SO4 per ounce stock solution. 0.055 gm K2SO4 times 7 ounces stock solution = 0.383 gms K2SO4 added to the one gallon fertilizer you are going to use.]

To make one gallon of fertilizer: add 7 fluid ounces of the stock solution of K2SO4 to an empty gallon container. (0.383 gm K2SO4) Fill with water as above and then add 1/2 tsp of Dyna-Gro 7-8-6. Mix and use.

If this does not help, and you can read and use Excel spreadsheets and know some chemistry, I'd be glad to send you my calculation spreadsheet. You'll have to PM me your email so I can send it to you.

[jerrytheplater]

Samreu. I did just look at your calculator and saw it is using the density of K2SO4 as a crystal/solid. You can't use that for ground chemicals. There is way too much air in-between the grains of chemical. That is why weight is always best.