Substrate Comparison Tool

Compare growing media side-by-side. Coco, peat, rockwool, soil, hydroponic — water holding, drainage, CEC, lifecycle, cost, compliance.

Compare two substrates

Substrate A

Substrate B

All substrates at a glance

Substrate	Type	Water holding	Drainage	CEC	Reuse cycles	OMRI/NOP	Typical cost
Coco coir (buffered)	Hydroponic-like	High	Excellent	Moderate	2-4	Yes	$$
Coco coir (unbuffered)	Hydroponic-like	High	Excellent	High (binds Ca/Mg)	2-4 after buffering	Yes	$$
Peat blend (ProMix BX etc.)	Engineered soil	High	Good	Moderate-high	1-2	Some yes	$$
Rockwool slabs	Hydroponic-inert	High	Excellent	None	1 (single-use) or 2-3 sterilized	No (mineral wool)	$$$
Rockwool cubes	Hydroponic-inert	High	Excellent	None	1 (propagation)	No	$$
Perlite	Hydroponic / amendment	Low	Excellent	Very low	2-5	Yes (mined)	$
Vermiculite	Amendment	High	Moderate	High	2-3	Yes (mined)	$
Hydroton / clay pebbles	Hydroponic-inert	Low	Excellent	None	5+ (cleaned/sterilized)	Yes (mined)	$$
Living soil (super-soil)	Soil with biology	High	Good	High	Indefinite (no-till)	Yes (compliant materials)	$$$ initial; $ ongoing
Outdoor field soil	Native soil	Variable	Variable	Variable	Indefinite	Per soil + amendments	—
Deep Water Culture (DWC)	Hydroponic (no media)	Reservoir-based	Recirc	None	Reservoir refresh weekly	Yes (water + nutrients OMRI)	$$$$ infrastructure
Mushroom: hardwood sawdust	Mushroom substrate	High	Moderate	—	1 (1-3 flushes per block)	Yes (untreated)	$
Microgreen mat (hemp/coco)	Microgreens	Low	Excellent	None	1	Yes (varies per product)	$$

How to choose

Goal	Recommended
Lowest learning curve	Engineered peat blend (ProMix BX); forgiving moisture buffer
Hydroponic precision (drain-to-waste)	Coco coir buffered or rockwool slabs
True hydroponic (no media)	DWC or NFT
Living biology / regenerative	Living soil with mycorrhizae and Trichoderma
Cannabis "no-till" multi-cycle	Living soil 15-25 gal pots; top-dressed
Microgreens commercial	Coco coir mat or hemp mat in 10×20 trays
Mushroom commercial	Pasteurized hardwood sawdust + bran "masters mix"
Outdoor / field	Native soil with annual amendments based on soil test
Lowest cost long-term	Living soil (high upfront, indefinite reuse)
Easiest disposal	Coco coir (compostable), peat (compostable)
OMRI / organic strict	Living soil with mineral amendments + biology; or coco with OMRI feed

Substrate-specific notes

Coco coir

Coco is "soilless hydroponic-like" — it drains like rockwool but holds water like soil. Cation Exchange Capacity (CEC) is significant: unbuffered coco binds Ca and Mg from your nutrient solution before plants can access them, causing deficiencies. Buffered coco has been pre-treated with Ca and Mg to fill these binding sites. Always buy buffered or buffer yourself before first use.

Coco breaks down over 2-4 cycles; structure degrades and water retention shifts. Reuse with caution; commercial growers often single-use.

Rockwool

Rockwool is essentially inert — minimal CEC, no buffering. Whatever EC and pH you feed is what reaches the roots. This makes recipes precise and predictable, but unforgiving — small recipe errors hit the plant immediately.

Slabs are typically single-use in commercial settings, though sterilization for 2-3 reuses is common in smaller operations. Rockwool isn't biodegradable; disposal can be a concern in some jurisdictions.

Living soil

Living soil systems prioritize biology — mycorrhizal fungi, Trichoderma, beneficial bacteria, earthworms — over pure chemistry. The substrate is amended once at setup with mineral inputs (rock phosphate, kelp meal, basalt, sul-po-mag), microbial inoculants, and stabilized organic matter (vermicompost, aged compost). Plants are top-dressed with additional amendments throughout the cycle.

Multi-cycle reuse is the design principle. A well-built living soil bed gets better over years as biology establishes. Initial setup cost is higher, but ongoing cost is minimal (top-dressings + compost teas).

Hydroponic (true)

True hydroponic systems (DWC, NFT, aeroponic, fogponic) use no substrate at all — roots are suspended in or sprayed with nutrient solution. Maximum control over root-zone chemistry; maximum risk of system failure (pump failure = wilt within hours).

Best for high-value crops where the precision pays off. Lettuce, herbs, microgreens, and high-end cannabis are common.

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