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Is pumice better for cactus and succulent mix and such than perlite? Is it all about the chunks?

I am thinking of making my own soil mix for succulents and cactus and other plants like jade plants and crassula, Echeveria, Snake plant, Aloe Vera etc.

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The difference when it comes to use for succulent plants comes down to a few things. Pumice is rock. Perlite is expanded volcanic glass. They both can hold water but in very different way. Perlite can absorb water as long as it's in contact with something wet. In other words, it looses water as soon as the soil is dry. Pumice has pores that collect water and oxygen in them. These pores hold water and nutrient reserves even after the soil dries up. It also hold oxygen in those pores. So, even if you pour too much water into the pot there are still air pockets for the roots. Perlite does neither of these things. It is very light weight and easy to work with. Some of it will float to the surface. If you are using a large amount like 50% perlite to 50% soil an awful amount of perlite will float to the surface. This will leave the bottom of the pot with just soil and no perlite.

Pumice is still light weight, but it is still a rock, so it weighs more than perlite. In a very large container perlite is a better option. There are not tons of succulents that will be getting that large. I use both. They both serve a purpose. Perlite is much cheaper for me. So, it is good for me to use both in most of my planters. But, if I were to choose between the two, I would go with pumice.

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  • Perlite is cheaper for a reason – seedelicious Jan 23 at 21:49
  • It's cheap because there is lots of it. It is easy to mine. It also has the biggest demand. Demand often sets price. When I worked at a garden centre we would sell 30 bags or more of perlite to pumice. Only the bonsai and succulent growers wanted to use pumice. So the price is more expensive. Which is why scoria is the most expensive. – GardenGems Jan 23 at 21:53
  • Its cheaper as it's an alternative to the real deal – seedelicious Jan 23 at 21:55
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I prefer pumice and something called TurfaceMVP (calcined clay) in my potting media. Perlite floats and clings around the base of the plant after watering. it also breaks down faster than the other two. There is also a product you can get from NAPA auto parts stores called NAPA 8822. It's a calcined clay oil absorbent. I used Turface because it's specifically made for agricultural purposes, but I know a number of people who use it.

My mix is: 30% Turface, 30% pumice, 20% large sand/small gravel, 20% coir.

I live in Arizona so my mix retains a bit more moisture than would be appropriate in a more humid environment.

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    Calcined clay and NAPA are not available in India. – 4-K Jan 16 at 17:35
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If you will be living In the same space as the pots then use pumice.

Perlite is 'glass popcorn', its benefits are noticeable in industrial scale agriculture.

In residential settings it is advised not to use perlite especially if you are living in the same room , as it difficult to contain and may get crushed when movingthe pots moving around or more likely to float to the top diring watering and eventually fall out.

Perlite dust is not healthy for humans. Whilst perlite is safe when damp, when it is dry it is very light making it susceptible to being airborne.

The dry glass dust is so fine, that it should only be used in a well ventilated area whilst wearing a dust mask!

You should only use perlite if you know how to contain it in the pot.

Which involves layering your soil, I use coco coir/sand at the top and bottom with the compost and perlite in the middle, the aim is preventing the perlite from falling out of the pot. bottom watering also keeps it from floating to the top!

Both perlite and pumice are used as they aid oxygen levels in the soil by providing good drainage and actually releasing oxygen when they are wet eg. during watering of the pots.

Perlite is lightweight and that's one of the reasons it's used industrially.

It's not just about the chunks.

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  • @seeddelicious I think you should back up your fact about the dangers of homeowners using Perlite with some data. Find a study that reports the small amounts inhaled by the homeowner is a danger to their health. – GardenGems Jan 20 at 0:42
  • @seeddelicious I mean you state it as a fact. If it is a fact you should be able to back it up. Or did you hear about this from someone else and repeating what you heard or maybe you read it on the internet. – GardenGems Jan 20 at 0:52
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    Dusts with less than 1 percent quartz are considered inert, or “nuisance dusts,” but research over the last 20 years has shown that many, perhaps all, dusts previously considered inert can cause serious health effects. ... The main dust-related diseases affecting construction workers are: Lung cancer. Silicosis. COPD. Asthma. Read more here – seedelicious Jan 20 at 2:00
  • Chemical composition of Perlite from various sources. "respirable crystalline silica in the form of quartz or cristobalite dust is carcinogenic to humans (Group 1). Occupational exposure to crystalline silica can cause silicosis and increase the risk of pulmonary tuberculosis. These exposures have also been linked to the development of autoimmune disorders, chronic renal disease, and other adverse health effects". – seedelicious Jan 20 at 2:19
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    residential meaning indoors eg. Living room or bedroom or in my case every room! It blows off the top and it gets crushed under the pots. – seedelicious Jan 20 at 5:16

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