# Lava rock



## Shadow (Jul 30, 2007)

I use lava rock as a component for paph potting medium. And I love it. But it is quite hard to find thing in my area and it is very expensive. My question is - how can I treat the pieces of lava rock in order to eliminate the salt built and to reuse it? Is it possible?


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## Leo Schordje (Jul 30, 2007)

Soak the lava rock in pure water for several weeks. Use rain water, RO, DI or Distilled water, which ever of them is cheapest for you to get. You can add a little vinegar or citric acid to help dissolve the calcium salts. (a couple tablespoons per gallon, 15 to 45 ml/ 4 liters) Rinse several times. Then let dry and see if the salts have dissappeared.


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## Candace (Jul 30, 2007)

You'll also want to sterilize it before reuse.


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## Hien (Jul 30, 2007)

Leo Schordje said:


> Soak the lava rock in pure water for several weeks. Use rain water, RO, DI or Distilled water, which ever of them is cheapest for you to get. You can add a little vinegar or citric acid to help dissolve the calcium salts. (a couple tablespoons per gallon, 15 to 45 ml/ 4 liters) Rinse several times. Then let dry and see if the salts have dissappeared.



Leo,

Does citric acid, vinegar also dissolve other harmful salt too or just calcium salts?
Do you have to soak them, or just let the rain water wash over it? (I left the clay pebbles out in the rain for couple weeks now, but the pots have holes underneath)


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## bwester (Jul 30, 2007)

Vinegar should dissolve all unwanted deposits.


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## Shadow (Jul 30, 2007)

Thanks for suggestions! But can the vinegar harm the plants afterwards? Or the amount of vinegar is too small to harm something?


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## gonewild (Jul 30, 2007)

The visible presence of "salts" on lava doe not necessarily mean they are harmful salts. As Leo stated soaking in water the lava will dissolve most of the salts. If there is still a whitish substance after soaking then it is probably not very soluble and as such shouldn't hurt the plants.


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## Kyle (Jul 30, 2007)

I agree with Leo and Lance, but have one question - What will the effect be on roots if they come into contact with those salt deposits? 

Kyle


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## gonewild (Jul 30, 2007)

Kyle said:


> I agree with Leo and Lance, but have one question - What will the effect be on roots if they come into contact with those salt deposits?
> 
> Kyle



Probably similar to the same effect as when the roots come into contact with limestone. I think you should call the insoluble deposits "mineral" deposits rather than "salt" deposits. Harmful salt deposits are harmful because they are generally readily soluble in water. The mineral deposits may in fact be beneficial to the plant.


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## Shadow (Jul 31, 2007)

gonewild said:


> The visible presence of "salts" on lava doe not necessarily mean they are harmful salts. As Leo stated soaking in water the lava will dissolve most of the salts. If there is still a whitish substance after soaking then it is probably not very soluble and as such shouldn't hurt the plants.



Well, the presence of the salts is not visible. I've just assumed that they are there, because I 've been using tap water for a year or so. But I can't see anything white on the pieces of rock. Does it mean that they are free from salt? The tap water in my area is not hard, but it is definitely not distilled either.


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## gonewild (Jul 31, 2007)

Shadow said:


> Well, the presence of the salts is not visible. I've just assumed that they are there, because I 've been using tap water for a year or so. But I can't see anything white on the pieces of rock. Does it mean that they are free from salt? The tap water in my area is not hard, but it is definitely not distilled either.



Are your plants suffering? Or showing signs of problems that may be related to soluble salts? If not don't worry about it.
A simple soak in water as Leo suggested will remove most or all of any salt deposits that might be on the lava surface. It is not likely there are salt deposits deep inside the stones.


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## goldenrose (Jul 31, 2007)

Shadow said:


> I use lava rock as a component for paph potting medium. And I love it. But it is quite hard to find thing in my area and it is very expensive.


Is lava rock used for landscaping/mulch outdoors in the Ukraine? It is in the U.S. A nursery/garden center carries it & that's probably the cheapest way to get it. If it's too coarse/chunky, you can take a hammer to it & break it down to whatever size pieces you desire.


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## Shadow (Jul 31, 2007)

gonewild said:


> Are your plants suffering? Or showing signs of problems that may be related to soluble salts? If not don't worry about it.
> A simple soak in water as Leo suggested will remove most or all of any salt deposits that might be on the lava surface. It is not likely there are salt deposits deep inside the stones.


No, they are not suffering. I just want to reuse the pieces that have already been used.


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## Shadow (Jul 31, 2007)

goldenrose said:


> Is lava rock used for landscaping/mulch outdoors in the Ukraine? It is in the U.S. A nursery/garden center carries it & that's probably the cheapest way to get it. If it's too coarse/chunky, you can take a hammer to it & break it down to whatever size pieces you desire.


No. We don't have volcanos here and all lava is imported and used in aquariums and terrariums only for decoration. That's why it is so expensive.


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## gonewild (Jul 31, 2007)

Shadow said:


> No, they are not suffering. I just want to reuse the pieces that have already been used.



Just rinse it in water and all should be well. Reuse it without worry, that is a big benefit of inorganic media.


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## Shadow (Aug 1, 2007)

Thanks a lot !


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## Leo Schordje (Aug 1, 2007)

Sorry, I've been away a couple days. Lance & the rest covered what I would have added. 
Leo


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