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Coco Coir
Definition: Coco coir is a soilless growing medium made from the fibrous husks of coconuts. It holds water well while staying airy, carries almost no nutrients of its own, and is usually blended with perlite. Cannabis grown in coco is fed nutrients with most waterings, giving fast growth and close control over feeding.
How Coco Coir works
Coco sits between soil and hydroponics. It looks and handles like a potting mix, but because it’s inert, the grower supplies all the nutrition, much like hydro.
Forms and prep
- Compressed bricks: cheap and compact; soak in water and they expand several times in volume.
- Loose bags: ready to use, often pre-washed and buffered.
- Buffering: raw coco holds sodium and potassium and grabs calcium and magnesium. Buffered coco has been pre-treated with a calcium and magnesium solution to prevent early deficiencies.
The usual mix
Most growers blend about 70% coco with 30% perlite for drainage. Some go 50/50 for very frequent watering.
Watering and feeding
- Feed with nutrients at almost every watering, typically at EC 1.0 to 1.8 depending on stage.
- Keep pH between 5.8 and 6.2.
- Water until 10 to 20% runs off to prevent salt buildup.
- Never let coco dry out completely; once established, many plants need water daily or more.
Why growers like it
Coco holds plenty of air even when wet, so roots grow quickly and overwatering is harder than in soil. Growth rates approach hydro without pumps and reservoirs. It also tends to carry fewer soil-borne pests.
Trade-offs
You need to water often, measure pH and EC regularly, and add Cal-Mag with most feedings. Miss a few waterings during peak flower and plants can wilt fast.