Rhizo FAQ's
Work backwards from the finished plant. As a rough guide, short vegetative periods and small plants suit 8L to 12L, a standard indoor plant grown to around a metre suits 23L to 30L, and long veg or outdoor plants justify 56L or 78L. Also check the tent footprint — four 30L pots take much more floor than nine 12L pots.
Yes, and that is the trade-off. Water evaporates through the whole fabric wall as well as from the surface, so you will water more often than with plastic of the same volume. In return you get far better oxygen in the root zone and it is much harder to overwater. On a RhizoStand with air underneath, expect to water more often again.
When a root reaches the fabric wall it meets air and stops growing rather than turning and circling the pot. The plant responds by branching further back, producing a dense fibrous root mass instead of a spiral of thick circling roots. More root tips means more surface area for water and nutrient uptake.
Every size from 16L upwards — 16L, 23L, 30L, 39L, 56L and 78L. The smaller 3.8L, 8L and 12L pots are supplied without handles because they are light enough to lift by the rim. On the big sizes handles matter: a saturated 56L pot is heavy, and lifting fabric by its edge is how fabric tears.
Not strictly, but a fabric pot sitting flat in its own runoff loses much of its drainage advantage and the base stays wet. A stand lifts the pot so it drains freely and gets airflow underneath, which also helps air-prune the bottom roots. The small stand takes pots up to 16L and the XL takes pots up to 39L.
Yes. Shake out the old medium, wash them and let them dry completely before storing. They will stain and the fabric softens with use, neither of which affects performance. Replace them when the fabric thins enough to tear at the seams or handles, which on regular use is typically after several runs.