Best Coco Coir for Hydroponics and Soil

Coco coir behaves like soil but feeds like hydro — it holds water and air at the same time, and it's inert, so you control every nutrient the plant sees. Two things decide whether it works: whether it's been washed and buffered properly, and whether you feed Cal-Mag from day one. Below is every coco medium we stock, from $10 bricks to full pallets, grouped by form so you can find the one that fits how you grow.

Which form of coco do you need?

Buffered vs unbuffered coco

Raw coco is loaded with sodium and potassium. Those ions sit on the same exchange sites that calcium and magnesium need, so untreated coco will lock out Cal-Mag for the first few weeks and show you what looks exactly like a deficiency.

Buffered (pre-treated) coco has already been soaked in a calcium solution to displace that sodium. Buy it buffered and you can plant straight into it. Unbuffered coco is cheaper — soak it in a Cal-Mag solution for 8–24 hours before use, then drain. Don't skip that step to save a day.

RHP certification is the quality mark worth paying for. It means the coco was washed, buffered and tested for EC and sodium content by an independent standard, rather than by the seller.

Coco coir vs soil

Coco-based potting mixes (Coco Loco, Cocosoil) sit between the two — they're amended, so they feed the plant for the first few weeks like soil, then behave more like coco.

Running coco correctly

Buying coco in bulk

Coco is bulky and light, so shipping is a large share of what you pay. Buying compressed — bricks, blocks and bales — moves far more growing medium per pound of freight than loose bags. For a commercial room, a pallet is typically less than half the per-litre cost of buying bags as you need them.

Pallet and case quantities are listed at the bottom of this page. If you need a quantity or a blend that isn't listed, contact us — most of these lines are available in configurations we don't stock on the shelf.

What to skip

• Unwashed, uncertified coco. The money you save goes straight into Cal-Mag and flushing.
• Letting coco dry out fully between waterings. Dry coco is hard to re-wet evenly, and EC spikes as it dries.
• Treating coco like soil and watering every three days. It wants daily.
• Starting seedlings at full feed strength. Coco is inert, but young roots still burn.

Frequently asked questions

Do I need to buffer coco coir?

If it's RHP-certified and sold pre-buffered, no. If it's raw or uncertified, yes — soak it in a Cal-Mag solution for 8–24 hours before use.

Why do I need Cal-Mag with coco?

Coco's exchange sites bind potassium and sodium in preference to calcium and magnesium, so those get locked out unless you supply extra.

What pH for coco coir?

5.8–6.2 going in and coming out. It's a tighter window than soil and closer to hydroponics.

Is coco coir better than soil?

It grows faster when you have your feeding dialled in, because you control every nutrient. Soil is more forgiving. If this is your first grow, a coco-based potting mix is a reasonable middle ground.

How much does a coco brick expand?

Roughly 5–7× its compressed volume. A standard 5 kg brick yields about 60–70 litres of usable medium.

Can I reuse coco coir?

Yes, more readily than most media. Remove the old root mass, flush thoroughly to reset EC, re-buffer with Cal-Mag, and treat the pH as unknown until you measure runoff.

Coco or coco-perlite?

Straight coco if you hand water. 70/30 coco-perlite if you're running drip or fertigating several times a day.

Related

All growing media · Nutrients and Cal-Mag · pH meters and testing · Pots and containers · Propagation trays and plugs