Tank's Green Stuff Horticultural Pumice 16 qt (15 lb) — lightweight volcanic rock for drainage & aeration

Tank's Horticultural Pumice is a lightweight, porous volcanic rock that boosts soil drainage, aeration, and moisture retention for potted plants.

Made from natural silica-rich pumice, this 16-quart (15 lb) bag is formulated for growers who want a stable, long-lasting soil amendment. Its irregular, porous particles hold water and nutrients in tiny pockets while leaving channel space for oxygen circulation — a balance especially valued by cacti, succulents, and indoor container plants. Use it to lighten heavy mixes, improve root zone airflow, and extend the life and performance of potting media.

How does Tank's pumice improve drainage without drying plants out?

The porous structure of pumice stores moisture within its voids while creating open channels between granules. This allows excess water to move away from roots quickly but also gives plants access to stored moisture as the soil dries.

• Porous particles absorb and release water gradually.
• Prevents waterlogging by improving macro- and micropore space.
• Reduces root-rot risk by balancing moisture and airflow.

Why choose pumice over perlite or sand in potting mixes?

Pumice combines several advantages: it’s heavier and more stable than perlite, so it won’t float to the surface, and it retains more water and nutrients than coarse sand. Its rough, angular grains also help maintain soil structure over time.

• Long-lasting texture — resists compaction and breakdown.
• Holds nutrients and moisture inside pores for microbes and roots.
• Natural silica content benefits soil structure and longevity.

How much pumice should I add to my potting mix?

The ideal ratio depends on plant type and current soil. For cacti and succulents, start with 25–50% pumice by volume; for houseplants that prefer lighter soil, try 10–30%. Adjust based on drainage performance and watering habits.

• Cacti/succulents: 25–50% pumice for fast drainage and aeration.
• General houseplants: 10–30% to lighten heavy mixes and improve airflow.
• Top-dressing or root-zone refresh: use a thin 1–2 inch layer around roots.

What practical benefits will I notice after adding this pumice?

Expect quicker drainage, reduced compaction, improved root health, and longer-lasting potting mixes. Plants typically show steadier growth because roots get oxygen and access to moisture stored in pumice pores.

• Less frequent repotting due to sustained soil structure.
• Fewer drainage-related issues like soggy soil or root stress.
• Cleaner top dressing that helps prevent soil crusting and runoff.

Who this is for: Tank's Horticultural Pumice 16qt (15 lbs) is designed for hobbyists and professional growers who want a durable, mineral-based amendment to optimize container soil. It's particularly useful for succulent and cactus enthusiasts, indoor gardeners coping with compacted mixes, and anyone wanting a natural, silica-rich material to improve soil aeration, drainage, and moisture management.