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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