SUBSTRATE & HARDSCAPE

Aqua Soil

Sintered clay granules that buffer pH down and release ammonia for the first weeks.

Setup stage Substrate

Unplug before servicingHands out of the water firstDrip loop on every cableTest before you dose30 ppm CO₂ ceilingCycle before stocking

Substrate

Specification
Material	Sintered clay
Granule size	2–4 mm (normal), 1–2 mm (powder)
pH effect	Buffers toward 6.0–6.8
Initial ammonia	Yes — drives first cycle
CEC	High
Depth	4–6 cm front, 8–10 cm back

Technical parameters
Ammonia release period	2–6 weeks
pH shift from tap 7.4	Falls to ~6.4
KH effect	Depletes carbonate hardness
Useful life	12–24 months
Shrimp-safe after	8–12 weeks of maturity
Layering	Base layer + powder cap

Aqua soil is not dirt. It is clay fired at high temperature until it becomes porous granules, which gives it two properties that no inert substrate has: a high cation exchange capacity, so it holds nutrients and releases them to roots, and an initial ammonia release that is a deliberate part of the product design.

That ammonia release is the reason a new aqua soil tank must be cycled before livestock go in, and the reason you should expect a nitrate spike in weeks three to six. It is also why aqua soil is not used in a shrimp tank until it has matured for two to three months.

The granules are light and must not be crushed or heavily disturbed. Aqua soil is usually laid 4–6 cm deep at the front rising to 8–10 cm at the back, which creates the visual sense of depth that most aquascaping styles rely on. It exhausts after roughly 12–24 months, after which root feeding or a rebuild becomes necessary.

Safety and welfare

Never stock a fresh aqua soil tank. The ammonia release will kill fish and shrimp within days.
Aqua soil strips KH, which removes the carbonate buffer. Test KH weekly for the first two months and be ready to adjust with a remineraliser.
Do not rinse aqua soil under a tap. It crumbles, and the fines turn the water to mud. If it must be rinsed, use tank water.

Using it well

Cap the base layer with a 1 cm layer of powder-grade soil. It looks finer, holds carpeting plants better, and stops the coarse granules showing through.

Slope the substrate so the back is roughly twice the depth of the front. It reads as perspective and costs nothing.

If you want a sand foreground, physically separate it with stones. Aqua soil migrates into sand over months and the boundary will blur.

Roots well for

Monte CarloHair grassStaurogyneCryptocoryneDutch style stem plants

Note. Parameters are conventional ranges across the category, not the claim of any one manufacturer. Nothing on this page is for sale and no outcome for any plant or animal is guaranteed. Simulator output elsewhere on this site is a simplified model, not a measurement — confirm everything with a test kit and the equipment's own instructions.

Aqua Soil

Using it well

Roots well for

Works alongside