The Types classification within market taxonomy separates substrates into natural gravel, synthetic sand, planted‑specific media, mineral‑enriched caviar gravel, and specialty engineered blends. Natural gravel, valued for its aesthetic versatility and low cost, captures the largest portion of the type‑based market, supporting both freshwater and marine setups that prioritize visual appeal over nutrient provision. Synthetic sand, engineered for uniform grain size and inert chemistry, serves approximately 20 % of sales, particularly in reef tanks where precise pH buffering is critical. Planted‑specific media, enriched with macro‑ and micronutrients, commands a premium segment of roughly 15 % as aquascapers seek optimal plant health and root development. Mineral‑enriched caviar gravel, a niche product (~5 %), offers high surface area for bio‑filtration and is favored in high‑tech setups. Specialty engineered blends, integrating porous ceramics or bio‑active compounds, occupy the remaining 10 % and are adopted by advanced hobbyists and research facilities seeking tailored water‑parameter control. Each type contributes distinct value propositions that collectively define the market’s structural composition.