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Black Diamond Blasting Sand, safe or no?

I have a 50lb bag of black diamond blasting sand around. I think I bought it initially intending to use it as an aquarium substrate.

I was wondering if it would be safe to use in a cp potting mix? It is primarily coal slag.

Here is a link to the MSDS:
http://www.ati-blackdiamond.com/products/msds-sheets.html

Other than material my only other concern would be whether the sand would damage roots. For its intended use I believe it is designed to be somewhat sharp?
 
I would plant a sacrificial sundew
 
I would plant a sacrificial sundew

Haha this can be done, maybe I'll pot up a D. capensis and possibly a spare Sarracenia division to see how they do through the season. Unless of course someone already has the answer still.
 
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Claims are made that coal slag is an inert material. Give it the acid (vinegar) test and let it sit for a day or so to see if there is any reaction.
 
Claims are made that coal slag is an inert material. Give it the acid (vinegar) test and let it sit for a day or so to see if there is any reaction.

It's believed to be inert by many people who use it as an aquarium substrate. I will do the vinegar test though.
 
Steve from the NECPS used this in his bog. Seems to be just fine.
 
Steve from the NECPS used this in his bog. Seems to be just fine.

That sounds pretty good to me, I'll definitely try it out for some Sarracenia then, maybe a mini bog.
 
Claims are made that coal slag is an inert material. Give it the acid (vinegar) test and let it sit for a day or so to see if there is any reaction.

If coal slag is chemically reactive, which I honestly don't know, it would likely be acidic already and wouldn't react with an acid. The fizz test is strictly to determine if a mineral sample is limestone. I think a more informative test would be to add some of the material to some distilled or ro water and let it soak a day. Then test the pH of the water.
 
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Testing the pH would certainly be useful but not everybody has pH meters or test strips/solutions. Access to vinegar is cheaper and more available.

If the slag is acidic in nature to begin with it will not react to the acidity of peat moss. If it is basic in nature it will. If left over compounds from the grinding process are basic they would be trace enough that you will get a quick reaction (fizz) and neutralize. If the slag itself is basic it will continue to react to the acid until either the H+ or OH- ions in the acid or base, respectively, are neutralized. Which is why I suggested leaving it overnight. Rinsing first can remove most of left over compounds from grinding - these tend to be salts or basic in nature.

Slightly acidic substrates are usually ok for most CPs. A few do well in basic substrates - Drosera linearis seems to prefer marl fens.

Chemically inert substances should not react with a weak acid or base or dissolve in water. Some substances will not dissolve in water and thus not affect the pH of water but still react to an acid or base. These are not inert.

Acid - base reactions result in salts, generally not something you want to have in the substrate for CPs.

If you have pH testing devices or materials by all means run tests.
 
  • #10
Testing the pH would certainly be useful but not everybody has pH meters or test strips/solutions. Access to vinegar is cheaper and more available.

If the slag is acidic in nature to begin with it will not react to the acidity of peat moss. If it is basic in nature it will. If left over compounds from the grinding process are basic they would be trace enough that you will get a quick reaction (fizz) and neutralize. If the slag itself is basic it will continue to react to the acid until either the H+ or OH- ions in the acid or base, respectively, are neutralized. Which is why I suggested leaving it overnight. Rinsing first can remove most of left over compounds from grinding - these tend to be salts or basic in nature.

Slightly acidic substrates are usually ok for most CPs. A few do well in basic substrates - Drosera linearis seems to prefer marl fens.

Chemically inert substances should not react with a weak acid or base or dissolve in water. Some substances will not dissolve in water and thus not affect the pH of water but still react to an acid or base. These are not inert.

Acid - base reactions result in salts, generally not something you want to have in the substrate for CPs.

If you have pH testing devices or materials by all means run tests.

^ +1 this
 
  • #11
And after you've done all that science I would use a sacrificial plant before potting up half your collection in untested media . I've heard stories of bad batches of peat or sand for example , just makes sense to me
 
  • #12
Anyone with a computer and $20 has access to a digital pH pen more than accurate enough for the purposes under discussion. Welcome to the 21st century.
 
  • #13
I will save the money and use one of many spare seedlings, I have a ph tester and still chose my method as I bet other factors than just acidity can kill plants, and I was welcomed to the 21st century 15 years ago,
 
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  • #14
A practical test with sacrificial plants is in order. Even in the 21st century with computer modeling and simulations the best engineers will still run practical tests to destruction.

On a photography forum digital camera users are routinely cautioned about using film era flash units. Some of these can back path a high trigger voltage on the order of 500-600 volts. This can burn out the circuitry of most modern DSLRs. The engineers at Pentax have said 30 volts is the maximum safe voltage for Pentax cameras. Some post claiming to be an Electrical Engineer claimed this is nonsense and voltage doesn't matter. I called his bluff and told him to put his money where his mouth is and attach a variable controlled voltage (and amperage equivalent to what 6volt batteries produce) output to the flash circuits of one of his cameras starting from 6 volts and test to destruction or up to 1,000 volts which ever came first. He declined of course.
 
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