EcoBio-Block Natural Volcanic Rock for Aquarium Clarity & Balance — 15–40 gal (Medium)

EcoBio-Block is more than a rock. It combines mineral-rich, porous volcanic rock with a neutral cement binder to actively interact with tank water, helping absorb pollutants and stabilize water chemistry. The result can be a cleaner, more balanced habitat for freshwater life without relying on constant dosing.

What makes EcoBio-Block different

Designed for real tanks, EcoBio-Block works with your filtration to maximize water contact with the rock’s porous structure. The result is a steadier environment that supports stable parameters as aquatics settle into a new routine.

• Skip weekly dosing and still maintain clearer water for up to 2 years
• No droppers or measuring required; drop it in and let the tank balance itself
• Three-step setup to get started with minimal effort
• Safe for a range of freshwater life including fish, turtles, shrimp, and frogs

How to use in your tank

• Rinse the stone in chlorine-free water
• Soak overnight in chlorine-free water to remove any loose particles
• Place near the filter outlet or an air stone so water can circulate through it

Most tanks show visible results in 2–6 weeks, with some faster responses. Slight cloudiness in the first week is normal as the tank settles in.

Safety and compatibility

EcoBio-Block is designed to be safe for delicate freshwater life and is suitable for starting new tanks, clearing cloudy water, reducing water changes, and minimizing odors. Monitor pH and standard water test parameters during the first weeks as conditions stabilize, and perform a partial water change if anything drifts too far.

Sizing and tank compatibility

The Medium stone is designed for 15–40 gallon tanks, fitting standard 20-, 29-, and 40-gallon community setups. It’s also available in Nano, Nano 2-Pack, Mini, Small, and other configurations. For heavily stocked tanks or poorer starting conditions, consider the next size up or use two stones for faster, stronger results.