Coco Coir Bricks, Blocks and Bales
Compressed coco is the cheapest way to buy growing medium, because you aren't paying to ship water and air. A 5 kg brick stores on a shelf and expands to roughly 60–70 litres in a bucket. The tradeoff is the ten minutes it takes to rehydrate. Below are the bricks, blocks and bales we stock, from single $10 bricks to commercial bales.
How much does a coco brick make?
| Compressed size | Expands to | Fills roughly |
|---|---|---|
| 650–700 g brick | 8–9 L | Two 1-gallon pots |
| 5 kg block | 60–70 L | Three to four 5-gallon pots |
| 11 lb (5 kg) block | 60–70 L | Three to four 5-gallon pots |
| Commercial bale | Varies — check the listing | A full room |
Expansion runs about 5–7× compressed volume. Chips expand less than fine pith.
How to rehydrate a coco brick
- Put the brick in a container at least three times its volume — a bathtub or muck bucket for a 5 kg block.
- Add warm water. Start with about 4–5 litres per kilogram and add more as it drinks.
- Wait 15–30 minutes, then break it up by hand.
- If it's unbuffered, soak in a Cal-Mag solution for 8–24 hours, then drain. Skip this and you'll chase a calcium deficiency for weeks.
- Squeeze-test: a handful should hold together and release a few drops, not a stream.
Bricks vs loose bags
| Compressed bricks & blocks | Loose bags | |
|---|---|---|
| Cost per litre | Lowest | Higher |
| Storage | Compact, shelf-stable | Bulky |
| Prep time | 15–30 min, plus buffering | None — open and plant |
| Shipping | Far cheaper per litre | Expensive, mostly air |
| Best for | Planned grows, bulk buying | Topping up, small jobs |
What to skip
- Rehydrating in a container that's too small. It expands more than people expect, every time.
- Cold water — it works, but slowly.
- Skipping the Cal-Mag soak on unbuffered bricks.
- Uncertified bricks with no stated EC. Cheap coco is cheap because it wasn't washed.
Frequently asked questions
How much coco does a 5 kg brick make?
Roughly 60–70 litres once fully expanded — enough for three to four 5-gallon pots.
How long does a coco brick take to expand?
15–30 minutes in warm water. Break it apart by hand as it softens to speed it up.
Do coco bricks need buffering?
Unless the listing says pre-buffered or RHP-certified, yes — soak in Cal-Mag for 8–24 hours before planting.
Are bricks cheaper than bagged coco?
Considerably, especially once shipping is counted. You're not paying freight on water and air.
Related
All coco coir · Coco-perlite blends · Growing media · Cal-Mag
