Compressed Coco Coir Brick (5 kg / 11 lb) Review (2026)
By The DIYPicks Team · Updated July 2026
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- Seed starting
- Amending soil
- Containers
A space-saving, renewable peat alternative that rehydrates into a clean, water-retentive medium. Ideal for seed starting and lightening heavy mixes, but you supply the nutrients.
Pros
- One compact 5 kg brick expands to about 70-75 quarts, so it ships and stores far smaller than bagged mixes
- Renewable peat alternative with near-neutral pH that holds up to ~10x its weight in water yet still drains
- Sterile, weed- and pathogen-free medium that is excellent for seed starting and cuttings
Cons
- Inert with almost no nutrients, so plants need added fertilizer beyond the seedling stage
- Must be soaked and broken apart before use, which takes time and a large tub
- Cheap unbuffered blocks can hold salts and lock up calcium/magnesium if not rinsed and buffered
Specifications
| Type | Compressed coconut coir growing medium / amendment |
|---|---|
| Composition | 100% coconut husk fiber and pith, triple-washed and buffered (low salt) |
| Organic | Natural peat alternative (many are OMRI listed) |
| With fertilizer | No (inert medium, add your own nutrients) |
| Bag size | 5 kg block, expands to ~70-75 quarts when hydrated |
| Best for | Seed starting, lightening mixes, and boosting water retention |