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Crushed lava rock instead of sand?

Dante1709

Nepenthes newbie
I've been thinking about repotting my nepenthes lately, which is in a mixture of sphagnum, peat and orchid bark, and I don't have much clean sand to mix in. Would it be possible to crush up some red landscaping lava rock into bits, and use it as sand? I'll most likely wash the minerals out of them, but I'm worried about how well it holds water or drains it. Also, how small should I crush it to?
 
Do you have a rock crusher? I do not advise trying to crush rock with a sledge hammer. 1) it is hard work. 2) the splinters get all over the place (you'll put out an eye!). Anything from aquarium gravel to perlite bit size should be ideal.
 
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I smash my basalt in a heshen bag with a sledge hammer, no flying rocks, there is basalt country near here so I collect some now and then, the bag stops rocks attacking you and the materials of the bag are strong, but more importantly plants are not poisoned by any of its components, otherwise (although not suggested) we have also used a small cement mixer to break the rocks up, but the machine was pretty hammered after.
 
I know others just use the lava rocks as is without crushing them. Seems to work fine with Nepenthes.
 
The lava rocks are rather large, because they are landscaping rocks, and although there are some smaller ones, I was thinking about placing them into a plastic bag and hammering them. I'm just a bit concerned about the mineral content ; I've been running it through hot water until it is clear, but I'm not quite sure if that's enough.
 
I spent the last two days washing and separating out some black lava rock I got. I use it in my ping mix but this time around I saved the sand that was left over. I am interested to see how that works. It took forever to get out all of the cloudiness though. I had to have looked like I was panning for gold those couple of days in the driveway lol.
 
I frequently use what is referred to as "lava gravel" in my Nep mix. I believe it's the same as what is referenced here, albeit a little finer. You can find it under that name at Home Depot/Lowes/Ace/Wherever. I find that it's a good addition, and does no harm to my plants. I don't see why you couldnt' add it, even it it was rather large. The smaller parts of your mix will fill in the gaps and it should work well.
 
I've been running it through hot water until it is clear, but I'm not quite sure if that's enough.

I don't have much to contribute, but I will share a tip I learned during my vivarium phase. When washing / rinsing media, always use -cold- tap water; the reason being, your hot-water heater adds some undesirables, salts and metals, etc, that build up inside it over time.

(Edit) Damn, sorry for the necro-post...I should know better by now. I was using the search function for something and then forgot this wasn't an active thread. >.<
 
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Try red cinder sand, commonly called track sand. I've just recently started using it for my sarracenia and flytraps. I like the look of it compared to perlite, and it gives peat a nice red tint. Right now, I have some nepenthes seeds that I sowed on a red cinder sand / peat mix. I haven't noticed any ill affects. I didn't bother to rinse the sand either. I bought my sand at a place that sells different products by the yard. It was about 50 dollars a yard, which is probably more than a hobby grower will use. I bought about $16 dollars worth and I'm set several years. If you find a place that sells it, you're going to want a truck. It's DAMN HEAVY! I filled a few small totes that I had in my truck. Once filled, I couldn't lift them out, and my car was making groaning noises as I drove home.
 
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I have since found the composition of my black lava rock. It comes from the basaltic lava flows at Black Mesa in the far western part of the pan-handle of OK and northeast corner of New Mexico. If your supplier also gets theirs from this region at least now you know what you got! I have yet to do much research on any negatives or positives but all of my plants have all seemed to do quite well with it mixed in (pings - extra small rocks and fine sand, neps - small to medium rocks). The best thing about the sand is it rarely compacts and sticks to itself once wet and then dried out. My silica sand tends to cake up once it dries out but the lava rock sand still stays loose and fluffy. My ping mixes use quite a bit of this lava rock sand.


 
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Now if only I remembered chemistry...

In any case, regarding Pings, they seem to like the mixes I make up with lava rock more than mixes without (but that could be due to the airy nature of the rock more than anything else).
 
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I would imagine that the 9% calcium would benefit the pings, I should also clarify, I smash it in a bag with a hammer, but only the ultra aerated stuff from west of here, if I get the basalt from north of here (solid black basalt) it is much harder and sends shards, makes dust not gravel and the bag is ruined at the end, so do not try crushing it unless you have a crusher.

Drosera Spathulata, adelae and several utrics and pings I have love Basalt.
I use large 1inch gravel for some of the nep pots and the pings, but the utrics (longifolia and livida) and the drosera like small 1cm gravel.

I have also tried sand, granite gravel and pumice with my pings, but basalt seems best, pumice would be but the shops here sell pumice collected from a beach, its fine for orchids but kills carns unless washed.
 
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I have since found the composition of my black lava rock. It comes from the basaltic lava flows at Black Mesa in the far western part of the pan-handle of OK and northeast corner of New Mexico. If your supplier also gets theirs from this region at least now you know what you got! I have yet to do much research on any negatives or positives but all of my plants have all seemed to do quite well with it mixed in (pings - extra small rocks and fine sand, neps - small to medium rocks). The best thing about the sand is it rarely compacts and sticks to itself once wet and then dried out. My silica sand tends to cake up once it dries out but the lava rock sand still stays loose and fluffy. My ping mixes use quite a bit of this lava rock sand.



What about red lava rock? I'm no expert on chemistry and what minerals Nepenthes are sensitive to, so what I'm asking is : does red lava rock leach significant amounts of harmful minerals, and can those minerals be washed from the stone?
 
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