The original poster of the question is in New Zealand. I’m not 100% certain, but based on NZ’s proximity to Australia, I’m assuming that there are reefs nearby.Yes that sand used in marine aquaria is mined from underwater areas in the Bahamas and a few other tropical places and even some inland places (ancient inland seas) with large calcium carbonate deposits/geology. It is from the local corals eaten and pooped out by fish and the shells shellfish and foraminifera, a tiny shellfish which is amazing that they occur in such numbers to make up a large component of the sand in those areas. In fact there has been a debate about whether the practice of mining it is sustainable.
In most of the world, beach sand is mostly quartz or other silica based minerals derived from weathering of rocks.
The black sand beaches in Hawaii and other areas with high volcanic activity is pretty cool too. Then there are a four places with green sand that has a mineral called olivine makes it green. Ive never seen that but it looks really cool in the pictures and kind of weird if youre used to the iconic white sand beaches.
The things that effect sand color on beaches is pretty fascinating.
What is Oolitic Aragonite? — Calcean Minerals & Materials LLC
Oolitic Aragonite: Nature’s Renewable Sand from the Ocean Beneath the gin clear waters of The Bahamian banks lies a unique mineral that looks much like sand but is unlike the sanwww.calcean.com
How is beach sand created? - Woods Hole Oceanographic Institution
Where does beach sand come from? The sand found on a specific beach is created by its surroundings. It’s unique to that beach—like a fingerprint.www.whoi.edu
Where Does The Sand On Our Beaches Come From?
Sands covering our beaches across the world can teach us a lot about Earth’s history.www.sciencefriday.com
Sand Color Palette - Coastal Care
Most beach sand color ranges from pale cream to golden to caramel, but in select places around the world, sand can be red, pink, orange, chocolate, gold, purple, green, or black.coastalcare.org
What the difference between Ocean sand and River sand
- Thread starter Pixar
- Start date
Pixar
Chumono
While New Zealand does not have coral reefs, we do have corals and we do have a responsibility to take action. Across the Pacific Ocean coral reefs are declining at a rate of about two percent a year, and it may be only 40 to 50 years before they're completely gone
Cajunrider
Imperial Masterpiece
I have been told I am an old fart who is full of it. If I unclench, there would be consequences.I'd rather enjoy myself... Some folks need to "un-clench"
MrFancyPlants
Omono
I collect Lake Erie “sand”… it is pretty chunky in places, but I like to sift it to get some specific sizes: smallest for seedlings, medium for top dressing. I don’t use the largest chunks as I buy lava for large size aggregates.
I know it is not quite applicable for OP except screening the sand can get some more desirable attributes if the sand is too fine. If in doubt soak it in some water to get the salt off.
Top layer of Lake Erie Sand:
I know it is not quite applicable for OP except screening the sand can get some more desirable attributes if the sand is too fine. If in doubt soak it in some water to get the salt off.
Top layer of Lake Erie Sand:
Paradox
Imperial Masterpiece
As Pixar stated, they do have corals but not extensive reefs. New Zealand is at the southern end of the range that coral can currently survive so they probably cant form extensive reef systems like elsewhere. So there probably isnt enough for a large amount of calcium carbonate to be in the sand.
In fact, the sand changes quite a bit around the islands of New Zealand and is derived by the interesting geology. The west coast of the north island has black sands whose color is attributed to high iron levels in the sand. Their white sand beaches is made mostly of quartz. They have gold sand beaches that is mostly iron oxide in granite. There are some shell beaches but apparently overharvest of shellfish is actually causing a problem on those beaches in that there arent enough shellfish naturally dying to supply shell for the beaches.
Even Australia beaches are made mostly of quartz derived from the erosion of the continent.
I think the only places you see a large amount of coral derived sand is smaller tropical islands such as the Caribbean and the Bahamas which is where the live coral sand you see for salt water aquariums comes from. Ive used it myself in salt water tanks over the years.
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Paradox
Imperial Masterpiece
While New Zealand does not have coral reefs, we do have corals and we do have a responsibility to take action. Across the Pacific Ocean coral reefs are declining at a rate of about two percent a year, and it may be only 40 to 50 years before they're completely gone
Beautiful picture and yes it is a sad reality that corals all over the world are declining.
I would still caution you against using ocean beach sand for your trees.
Also you might want to check your local laws. A lot of island nations make taking sand from the beach illegal.
In fact I even think its illegal where I am because of all the problems we have here with beach erosion.
Shibui
Imperial Masterpiece
This also applies to the rest of the world. Sands - beach, river or lake are derived from the local geology so will be composed of whatever has been washing down the rivers and eroding from the coastal rocks for the last million years or so.
Limestone sands are not all derived from current living reefs. We have extensive limestone geology in areas where no modern reefs could survive. Those are derived from ancient reefs when climate and position of the continents was different. Some limestones are derived from ancient shell beds, not from coral as such.
Even in areas of limestone the beach sands tend to be more silica because limestone is usually soft and gets ground to dust by wave action. It also dissolves slowly in most water so calcium carbonate is not usually a big component of beach sands except in areas adjacent to limestone geology
It is easy enough to test for calcium carbonate sands with an acid - vinegar should even cause some reaction - bubbles of CO2.
Why do people want "sharp" sand? It stacks better than round/ smooth sand, does it not? It has flat sides. I dont think sharp sand has significant depressions that would make air holding capacity superior to round sand grains.
If its quarz based its just rock, with no porosity. Maybe ocean sand created by various life forms (shells, skeletons) has some porosity depending on location but I wouldnt bet on a large effect.
Some beaches have volcanic materials, even pumice. Otherwise Id stay away from sand for bonsai. If you must use simply rocks, use the larger particles: grid. But even broken clay pots would be better.
If its quarz based its just rock, with no porosity. Maybe ocean sand created by various life forms (shells, skeletons) has some porosity depending on location but I wouldnt bet on a large effect.
Some beaches have volcanic materials, even pumice. Otherwise Id stay away from sand for bonsai. If you must use simply rocks, use the larger particles: grid. But even broken clay pots would be better.
Paradox
Imperial Masterpiece
Yes local sands are dependent on local geology. I alluded to as much with regards to Hawaiian sands.
I also stated that aragonite (calcium based) sands can be mined from areas that had ancient inland seas.
Beaches in the Caribbean tend to have more calcium based particles because the islands are far from the continents and there typically isnt a large source of silica based soils nearby. So sand on those beaches are derived from fish that eat coral and poop it out and from foraminifera and other things that make calcium carbonate shells.
Yes, silica based sands are very durable and dont dissolve easily unlike calcium carbonate. Quartz is hard so it can withstand the pounding of waves, movement of water, and friction from other particles better than a calcium based sand. The composition of the earth's crust is also a big factor. Oxygen and silica are the most common elements in the earth's crust by weight (approximately 46% and 27% relatively)., whereas calcium is 3.7%. Approximately 60% of the earth's crust by weight is made of quartz (Silica dioxide).
Paradox
Imperial Masterpiece
I think the idea is that the sharp sand is more irregular in shape and will resist compaction better than the round, more uniform shaped sand.
However I agree with your comment about one vs the other regarding air I dont think it would make much of a difference either.
I hadnt thought about it, but you are right about the fact that quartz has no porosity which is one of the reasons we use lava and pumice.
We want that porosity.
In my experience the sand still compacts because of the smaller particle size.
Lava and pumice are also much lighter.
Pixar
Chumono
I'm surrounded by beaches - Coast to Coast distance is only 60 miles ( Tasman Sea on West Coast - Pacific Ocean on the East Coast ) I also have the Waikato River only 10 miles away
Why would I use broken clay pots instead on using sand which is a natural resource ?
Paradox
Imperial Masterpiece
Not entirely sure why you bothered to ask the question since you seem to have already made up your mind regardless.
Many of us have tried the free or cheap alternatives to bonsai soils and found it not worth the little bit of money we saved in the end.
I hope you dont do harm to your trees using salty ocean sand.
Pixar
Chumono
No problem with the trees I have , as I said I'm using less than 5% total with my soil mix .
Crazy Diamond
Omono
Hi from Tenerife hehe the black sand is mostly volcanic but it also haves some crustacean shells so It can rise the pH, I use It for aquariums hehe
Wires_Guy_wires
Imperial Masterpiece
How's the weight of the sand? Do you think it would be expensive to ship 0.5L?
Because I'm waiting for my blaauw junipers to produce more berries for you. Would be a fun trade if it's not too expensive.
Pixar
Chumono
Wonder why we have Pine trees growing as forest in river and ocean sand ? The forest has been there for years
rockm
Spuds Moyogi
"Sand" for bonsai is not what people unfamiliar with bonsai think of as sand, just like bonsai "soil" isn't dirt. Japanese "river sand" used in bonsai soil is far more angular and granular than regular "sand."
www.superflybonsai.com
Sure, you can use whatever you collect, but it's not really what's recommended as "river sand" in bonsai soil. Beach sand is going to have salt content, as well as pH issues (sea water is probably going to be more alkaline than acid).
Kiryu - Japanese Bonsai Soil - Kiryuzuna
Kiryu is a porous, hard volcanic stone for mixing your own bonsai soil. In Japan it is commonly used the same way lava is used here in the United States. Japanese soil mixes commonly include Akadama, Hyuga Pumice and Kiryu. Kiryu translates to "river sand" in Japanese. Grain Size - 5mm - 1/16"...
www.superflybonsai.com
Sure, you can use whatever you collect, but it's not really what's recommended as "river sand" in bonsai soil. Beach sand is going to have salt content, as well as pH issues (sea water is probably going to be more alkaline than acid).
Why is angular good?"Sand" for bonsai is not what people unfamiliar with bonsai think of as sand, just like bonsai "soil" isn't dirt. Japanese "river sand" used in bonsai soil is far more angular and granular than regular "sand."
Kiryu - Japanese Bonsai Soil - Kiryuzuna
Kiryu is a porous, hard volcanic stone for mixing your own bonsai soil. In Japan it is commonly used the same way lava is used here in the United States. Japanese soil mixes commonly include Akadama, Hyuga Pumice and Kiryu. Kiryu translates to "river sand" in Japanese. Grain Size - 5mm - 1/16"...
Sure, you can use whatever you collect, but it's not really what's recommended as "river sand" in bonsai soil. Beach sand is going to have salt content, as well as pH issues (sea water is probably going to be more alkaline than acid).
penumbra
Imperial Masterpiece
It doesn't pack easily.Why is angular good?
I really think that should make it pack easier than if the grains were round. You think the pointy bits just push each other away, but I think the flat sides will stack.
Try stacking marbles vs. glass shards
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