Universal Substrate

In this guide, you will learn how to select a weed substrate of quality, what proportions and grain sizes are suitable for each phase, and how to integrate it with fertilizers whether mineral or organic. It includes FAQs and links to key categories of Pevgrow to set up your cultivation from start to finish.

What is Universal Substrate and why is it suitable for most crops?

We call universal substrate for cannabis the ready-to-use mix that combines peat (light and/or dark), plant fibers such as coconut or composted wood, and additives like perlite to improve aeration and drainage. Its main advantage is that it arrives factory-balanced, with a stable pH range (usually 5.8–6.5) and a moderate EC, sufficient to support initial growth without the risk of burns or blockages.

If you are looking for a medium that tolerates mistakes, that accepts progressive fertilization well, and that facilitates white and active roots, the universal substrate is a safe starting point. It adapts to small pots for seedlings and large containers during flowering, with intuitive management of watering and nutrition.

Optimal composition and technical parameters (pH and EC)

A good universal weed substrate usually includes:

• Light peat for water and cation retention without excessive compaction.
• Perlite (10–30%) for macro-pores that increase root oxygenation.
• Coconut fiber for structure, porosity, and rapid gas exchange.
• Limestone amendments to stabilize pH in a range compatible with cannabis.
• Optionally, mycorrhizae and Trichoderma to stimulate symbiosis and resilience.

Technical objective: pH 6.0–6.5 and EC 0.8–1.2 mS/cm at the beginning. This way, the roots explore easily, the plant assimilates macro and microelements, and you decide the intensity of fertilization without surprises. Remember to measure drainage (“runoff”) to validate that the pH/EC remain within range.

How to use the universal substrate step by step

1) Initial hydration: open the bag and moisten evenly, without soaking; look for a fluffy mix that does not drip when lightly compacted. 2) Transplanting: fill 2/3 of the pot, place the root ball, and complete without excessive pressure to preserve air pores. 3) Settling watering: apply water adjusted to pH with a low EC (only calcium/magnesium if your water is soft) until 10–20% drainage. 4) Progressive fertilization: start gently (EC 1.2–1.4) and increase during growth and flowering according to the plant's response. 5) Drying management: lift the pot; if it feels heavy, wait. Good drainage and correct aeration prevent overwatering.

Tip: if your climate is very dry and hot, add slightly less perlite to retain more moisture; if your room is humid or you water frequently by drip, a larger fraction of additives speeds up the “dry-back.”

When to choose universal substrate over other bases?

The universal substrate is ideal if you prioritize simplicity and stability. Compared to a very loaded All Mix, it gives you more control over fertilization from early on; compared to pure coconut, it requires fewer daily waterings and is more forgiving for beginners. Additionally, it works perfectly in grow tents with high-intensity LED, where correct aeration limits humidity spikes in the substrate.

Common mistakes and how to avoid them

• Excessive compaction: reduces oxygen and slows growth. Fill without “squeezing.”
• Chronic overwatering: wait for the surface to lighten and the pot to lose weight; look for a stable watering-drying pattern.
• pH out of range: calibrate the meter and adjust before each watering.
• Not measuring drainage: without pH/EC data in runoff, blockages appear without warning.
• Excess salts: alternate waterings with plain water and perform preventive flushes if EC rises.

FAQ about universal substrate for cannabis

What is the difference between universal substrate and Light/All Mix?

The universal prioritizes balance and control of fertilization; Light Mix is even “lighter” in nutrients; All Mix comes more loaded and delays the first fertilization.

What are the recommended pH and EC?

Initial target pH 6.0–6.5 and EC 0.8–1.2 mS/cm, gradually increasing in high-demand phases.

Should I add extra perlite?

If you seek more aeration and quick drying, add 10–20% perlite; in dry climates, keep the mix as is to avoid accelerating evaporation.

Is it compatible with organic and mineral fertilizers?

Yes. The universal substrate is versatile and responds well to both, always adjusting pH/EC and observing leaf color and drying speed.

How often should I transplant?

When the root ball colonizes the pot (visible roots through the drainage holes and very rapid drying). Increase size to avoid stress and maintain growth rhythm.

Conclusion: simplicity, control, and results with universal substrate

The universal substrate offers the perfect midpoint between retention and porosity for healthy and productive cannabis plants. With correct watering management, a stable pH and EC range, and progressive fertilization, it becomes the safest base for obtaining aromatic, clean, and abundant harvests.

Take the next step: choose your genetics, calibrate lights and ventilation, and stock your nutrient plan with Pevgrow fertilizers. With a good universal weed substrate, the rest of the cultivation becomes more predictable and efficient.