Coco Perlite Mix - 70/30 and 60/40 Blends
Coco on its own holds a lot of water. Cutting it with perlite opens the mix up, drains faster and makes it much harder to overwater — which is why 70/30 coco-perlite is the default for anyone running drip or feeding several times a day. Straight coco suits hand watering; blends suit frequency. Below is every pre-mixed coco-perlite blend we stock, plus what to buy if you'd rather mix your own.
Which ratio do you need?
| Blend | Drainage | Best for |
|---|---|---|
| 100% coco | Slowest | Hand watering, once daily |
| 70/30 coco-perlite | Balanced | The default. Drip, 2–5 feeds a day |
| 60/40 coco-clay pebbles | Fast | High-frequency fertigation, large pots |
| 50/50 coco-perlite | Fastest | Very frequent feeding, humid rooms |
More perlite means more oxygen at the roots and less risk of overwatering, but it dries out faster and holds less nutrient between feeds. If you can't water daily, don't go past 70/30.
Pre-mixed or mix your own?
Pre-mixed blends are consistent bag to bag and save you a job. Mixing your own is cheaper at volume and lets you set the ratio — buy a coco brick or loose bag and add perlite by volume, not weight. Rinse perlite before mixing; the dust is an irritant and it clogs drippers.
Running a coco-perlite mix
| Variable | Target |
|---|---|
| pH (in and out) | 5.8–6.2 |
| Cal-Mag | Required — perlite doesn't change this |
| Runoff | 10–20% every feed |
| Feed frequency | 2–5× daily at 70/30 under drip |
Adding perlite doesn't remove coco's calcium and magnesium lockout — that's the coco fraction's chemistry. You still need Cal-Mag from day one, and the medium still wants buffering unless it's sold pre-buffered.
Frequently asked questions
What is the best coco to perlite ratio?
70/30 for most growers. Go to 50/50 only if you're feeding several times a day and your room holds humidity.
Do I still need Cal-Mag in a coco-perlite mix?
Yes. The perlite is inert and doesn't affect the coco's cation exchange behaviour.
Can I mix my own coco and perlite?
Yes, and it's cheaper at volume. Mix by volume rather than weight, and rinse the perlite first to remove dust.
Does perlite need to be pH adjusted?
No, perlite is pH neutral. Adjust the feed, and target 5.8–6.2 as you would with straight coco.
Related
All coco coir · Growing media · Cal-Mag and nutrients · pH meters
