# Best method to crush KCl pellets?



## Oqsy (Jul 3, 2004)

your method sounds better than mine. 

i use a rubber mallet, a cutting board, and whatever is available to drape over the pellets to keep the shrapnel from shooting around the room (cloth, paper, plastic). i've found that putting the pellets in a doubled or tripled set of wal-mart bags keeps the salt all together and easy to pour off into a container. the only downside is that the plastic is more likely to rip and make a mess than cloth. it takes much much longer than your method, and makes buying the bulk pellets much less attractive. maybe there's something like a super-industrial strength blender that could chop it up without burning up the motor or destroying the blades 

Oqsy


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## Rex Grigg (Dec 10, 2002)

There are a couple of things that come to mind. 

Food Processor.
Old style meat grinder
Coffee grinder

Any of those should work.


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## Momotaro (Feb 21, 2003)

Speaking of "old style"...

How about a mortar and pestle?

Mike


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## bharada (Mar 5, 2004)

Momotaro said:


> Speaking of "old style"...
> 
> How about a mortar and pestle?
> 
> Mike


The KCl pellets are about 3/4-1" in diameter. A bit too big for my motar an pestle.

The biggest problem I have is that the bat has a rounded end and very little mass. What I need is a 3-4" diameter steel rod, or at least a section of one that I could mount to a handle. Time to visi Harbor Freight and see if they have any cheap sledge hammers. Maybe I can take its handle off and rig it to one of the hammer faces instead. Turn it into a very small area tamping tool. A 5# sledge should make quick work out of the KCl.



Rex Grigg said:


> There are a couple of things that come to mind.
> 
> Food Processor.
> Old style meat grinder
> ...


I don't have any of these, although I did try using the chopping accessory for my Braun stick blender...that was a joke! :icon_lol:

I've seen those brass Turkish coffee grinders used to grind salt, but they can be pretty expensive, and I'd still need to break the KCl pellets into rock salt sized pieces.

The nice thing about the KCl is that once it's in powder form it dissolves very easily without all the insoluable residue common to K2SO4.


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## Momotaro (Feb 21, 2003)

> The KCl pellets are about 3/4-1" in diameter. A bit too big for my motar an pestle.


Get a bigger mortar and pestle! :hihi: 

Mike


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## bharada (Mar 5, 2004)

Momotaro said:


> Get a bigger mortar and pestle! :hihi:
> 
> Mike


:icon_lol:

You think I could sneak a 12-ton hydraulic press into my garage without my wife noticing? :hihi:


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## KevinC (May 24, 2004)

I know you want to dry-dose, but in this case it might be less trouble to dissolve a fixed amount of the large pellets in water for a concentrated dosing solution. You can get a LOT of KCl to dissolve!

Kevin


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## Oqsy (Jul 3, 2004)

that is what i do in the long run, but i don't have a very good system yet. i suppose hot or even warm RO water would be the best for dissolving the bigger pellets, but I don't yet have a very good mixing container or storage bottle. on top of that, i don't have any scales for weighing the dry KCl before mixing. the method I'm using now is to crush it finely and put it in my morton salt substitue container and dose the way I had been doing before. now it's been so long I can't remember how I did the math, but I should be pretty close with the dosing by teaspoons, and since K+ concentration is estimation more than N or P, a little overdose or underdose shouldn't present any significant problems assuming I keep up the water changes, and don't shock my catfish with sudden electrolyte shifts. (almost killed 2 clown plecos with a K+ overdose a few weeks back... long story)

Oqsy


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## bharada (Mar 5, 2004)

I actually mix up stock solutions for all my ferts (in 1ml=1ppm/10gal concentrations). I bought a cheap kitchen scale (max capacity is 500g) at Wal-Mart for measuring out the larger amounts of dry ferts (KNO3 and KCl/K2SO4). For stuff like KH2PO4 I use an old reloading single-beam balance. I have to convert grams to grains when using it, but I can be very precise measuring this way. Since I weigh out the dry ingredients for making these solutions, I need them to be in a powder form so that I can get close to the dry weight needed.

Anyway, while walking through the mall this afternoon I passed by a sporting goods store checked out their iron dumbells. I bough a 10# weight with (relatively) flat ends for $6, brought it home and sanded the paint off one end. It'll crush a KCl pellet with ease. Now what I need to find is a heavy, flat plate to crush the pellets on. The pie pan ends up flexing too much so the KCl granules bounce around while I'm pounding. I need to visit some local machine shops and see what kind of scrap steel plate they have lying around.


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## Rex Grigg (Dec 10, 2002)

> The nice thing about the KCl is that once it's in powder form it dissolves very easily without all the insoluable residue common to K2SO4.


Where are you getting your K2SO4 from? I have never had a problem with any residue.


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## bharada (Mar 5, 2004)

Rex Grigg said:


> Where are you getting your K2SO4 from? I have never had a problem with any residue.


I got it from Greg Watson. When I mix up my solutions I always have some insoluable black/brown powder at the bottom of the bottle.


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## KevinC (May 24, 2004)

If you make a saturated solution, you don't need a scale. At room temp, 1g of KCl dissolves in 2.8ml of water (35.7g in 100ml water). Put some water in a container then add KCl and shake to dissolve - repeat until no more will dissolve. This will cool the water, so let it warm back up and make sure there is still some solid on the bottom. Now 1ml of the solution will provide 0.357g of KCl (use Chuck's calculator from here). In this case you could assume 20 drops is about 1ml if you don't have a marked dropper. Again, since K is not that critical, if your temp is a little higher or lower or if you use tap to dissolve it, it probably won't matter.

Kevin


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