I'm having good results using perlite in my mix. However, there are few drawbacks which I am planning to overcome. The question is not about the cost but is an issue about renewability of perlite sources and health risks from dust. I add 50% perlite to my standard peat & coir potting mix. I have often recycled grit like scoria and river sand which tends to sink while peat & coir float on the water. I have switched to Perlite because it has better results. However, there are few issues which arise:

  • Perlite is prone to crumble so I must add new perlite to the one I recycle. That is not a deal. I intend introducing as little as perlite as possible, because of the dust and renewability. I normally dump degraded potting mix to my compost pile, but I don't want to add Perlite to it. Not even the perlite dust. FYI - I don't use tap water directly, but rather the same water I have gathered for watering my plants, so the water is not wasted.
  • I cannot separate it with water, because both the perlite and the coco-peat mix float together. Sifting with a sieve does not make a difference either. The sifting is possible only when the mix is dry, and there you have the first problem once again - dust.

I'm thinking of letting the mix dry and burn it. The coco-peat mix will turn into ashes which are easier to sift and take the Perlite. Does the coco-peat mix burn?

What other methods can I use to achieve this? Would pumice be an alternative to perlite?

  • I simply reuse the potting soil for potted plants (not for seedlings), and have had no problems doing so. My plants doe not have any diseases, however.
    – Jurp
    Sep 10, 2023 at 21:12
  • I may use it one or two more times. Usually, I repurpose it for the more robust garden plants, and not for the specialty (aroids, bulbs, cacti, Hoyas, Calatheas...). I dump it into the compost pile only when it is too degraded and becomes waterlogged. However, I cannot remove the perlite before doing this... Sep 11, 2023 at 17:06
  • I should've mentioned that when I reuse potting soil I make sure to also use a timed-release fertilizer, as there are no nutrients left in the mix by that point.
    – Jurp
    Sep 11, 2023 at 18:00


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