Most potting mixes need something added to stop them compacting over time and coconut coir used 50/50 with potting mix can help with this and make it easier for the roots to grow.
Perlite can be used to increase drainage. Most mixes have 20-30% perlite and 70-80% potting mix (either straight potting mix or coconut coir with potting mix). The perlite and potting mix are measured by volume not by weight. You use a plastic container (eg: 4 inch garden pot) and take 3 scoops or perlite and 7 scoops of potting mix. Put that in a container and mix it up then use that for the plants.


