I designed and printed these adapters, which fit into used glass bottles. I use them to grow lettuce, basil, and more.
I will publish the files very soon and also make a post about them :)

Right now, I’m trying different materials to use as substrate for holding the seeds, but most I tried sucked in one way or another.

  • LECA is too coarse, and the balls roll out.
  • Coco coir is washed out quickly when filling the bottles/ when raining, and rots in the nutrient solution
  • Polyester filling (used for pillows) is either completely soaked, or bone dry, but works reasonably well
  • PVA sponges become too hard when dry
  • Cotton/ other cellulose stuff (towel, etc.) decompose too quickly

Can you suggest me other materials that would be best suited for that purpose?

  • nettleEnglish
    3·
    23 days ago

    Spagnum or some other moss (preferably home grown). if you buy it make sure to get the stuff that is still slightly alive (dried not toasted else it will rot and not work very well.

    Most “sustainable” sources aren’t all that sustainable, but its my favourite substrate nonetheless, I’m currently trying to grow it myself (not very sucsesfully tho)

    • Günther Unlustig 🍄@slrpnk.netOPM
      2·
      23 days ago

      Great suggestion! I totally forgot about that! Spongy, wicking, doesn’t degrade fast, and the best thing: I’m also currently trying to grow it myself!

      (Still learning tho.)

      I collected many different samples from different places (forest, concrete, etc.) and see what thrives and what not

  • electric_nan@lemmy.ml
    3·
    23 days ago

    Use something coarse like ceramic balls. Drill some holes in your pieces level with the top of the substrate. Use pieces of wire or paperclips through the holes to hold the substrate in place.

  • FoxyFerengi@lemm.ee
    2·
    23 days ago

    Rock wool is good for hydroponics. It’s not good to handle bare-handed or breathe in because it can splinter, but it won’t have anything harmful in it that is unsafe for edible plants