Seiryu Stone
Grey-blue base with white calcite veins. Raises KH and pH slightly. Iconic for iwagumi aquascapes.
Aqua Soil can drop pH enough to offset the Seiryu buffer. Monitor KH weekly in planted tanks.
Dragon Stone
Also called Ohko stone. Weathered ochre-yellow, porous, with deep cavities. Inert chemistry — no pH/KH impact.
Brittle — store carefully, don't drop on glass. Best for nature-style and hobbit-hole aquascapes.
Lava Rock
Black or red volcanic stone, highly porous. Great for bio media and rooting moss. Inert chemistry.
Bacteria colonize deep inside pores, boosting biological filtration naturally.
Texas Holey Rock
White limestone with natural holes and caves. Buffers pH up to 8.0-8.4 — perfect for African cichlids.
Never use in soft-water planted tanks or discus setups — will crash your parameters.