ADA Aquasoil Amazonia Substrate Guide: Cycling and Layering

ADA Aquasoil Amazonia remains the benchmark planted-tank substrate because of one simple thing: it drops pH and releases ammonia in a controlled way that powers plants through the first three months of a scape. This ADA Aquasoil Amazonia substrate guide covers the 7-21 day ammonia spike every new scape produces, how to layer with Power Sand, the difference between Amazonia Version 2 and Light, and the practical cycling routine that gets a tank stocked safely. Gensou Aquascaping in Singapore has built dozens of Amazonia scapes under PUB water conditions and these notes reflect what actually happens.

Quick Facts

• Product: ADA Aquasoil Amazonia — baked organic soil pellets
• Ammonia spike: 4-8 ppm peaking days 3-7, clearing by days 14-21
• pH effect: drops tap water to 6.0-6.5 for 3-6 months
• KH effect: buffers KH down to 1-2 degrees
• Recommended depth: 40 mm front, 80-100 mm rear with slope
• Versions: Amazonia V2 (standard), Amazonia Light (reduced ammonia), Amazonia Powder Type (cap layer)
• Lifespan: 2-3 years before nutrient exhaustion

What Aquasoil Actually Is

Aquasoil Amazonia is organic topsoil, ammonium-rich clay and a proprietary binder baked at moderate temperature into 3-5 mm pellets. The pellets act as a cation exchange substrate, holding ammonium, potassium and trace elements and releasing them through plant root uptake. Unlike inert gravel, Amazonia is an active substrate — it actively changes water chemistry.

The acidic organic content drops KH and pH. In Singapore, where tap water sits at pH 7.5-8.0 and KH 2-4, a fresh Amazonia setup typically reads pH 6.2 and KH 1 within 48 hours.

The Ammonia Spike Cycle

Fresh Amazonia leaches ammonia from the baked organic matter for 7-21 days. Expect ammonia to rise to 4-8 ppm peaking around days 3-7, drop as nitrifying bacteria colonise the substrate and filter, and clear fully by days 14-21. This spike is the main reason Amazonia is fish-in-cycling unfriendly but plant-friendly — plants consume ammonium directly.

Do heavy water changes (50 percent daily for the first week, 30 percent every other day thereafter) to export ammonia and prevent plant melt from concentrated toxicity. Test ammonia, nitrite and nitrate daily with liquid kits; strips are too imprecise at these levels.

Power Sand and Layering

ADA specifies Power Sand as a base layer under Aquasoil. Power Sand is a porous volcanic pumice mixed with slow-release peat and organic additives — it supports deep root oxygenation and adds bacterial surface area. Layer it 15-25 mm thick across the base, with heavier coverage under future high-demand plants like Rotala or Cryptocoryne.

Top with 40-60 mm of Aquasoil Normal Type, then cap high-traffic visible areas with 10-20 mm of Powder Type for finer front-tank aesthetics. Total substrate depth should slope from 40 mm front to 100 mm rear for visual perspective.

Amazonia V2 vs Amazonia Light

ADA reformulated to Amazonia Version 2 in 2015 with slightly lower ammonia leaching than the original but the same active performance. Amazonia Light is a lower-nutrient version aimed at tanks with sensitive livestock like Caridina shrimp, reducing the ammonia spike to around 2-3 ppm peak.

For plant-only dark start scapes or pure plant tanks, standard Amazonia V2 is the right choice. For Crystal Red or Taiwan Bee shrimp tanks cycled with livestock in mind, Amazonia Light costs more but saves stock losses.

Dark Start vs Wet Start

A dark start fills the substrate with water only, covers the tank for two to four weeks, and lets cycling complete before plants go in. A wet start plants immediately and runs CO2 and lighting from day one. Both work; dark start is kinder to demanding plants like Hemianthus callitrichoides because they do not face full ammonia exposure.

In Singapore’s warm rooms (26-30 degC ambient), cycling completes faster than in temperate climates — expect the wet-start ammonia peak to clear by day 14.

Cycling Checklist

Plant heavily from day one if doing a wet start — at least 60 percent substrate coverage. Run filter and CO2 from first fill. Test ammonia daily. Do not add fish or shrimp until ammonia, nitrite and nitrate all read predictable — typically ammonia zero, nitrite zero, nitrate 5-20 ppm.

Maintenance Over Two Years

Amazonia is nutrient-rich for the first 8-12 months, then gradually depletes. Supplement with liquid fertilisers from month six: ADA Brighty K, Green Brighty Mineral and Iron. By months 18-24 you will see reduced plant growth rates even with fert dosing — that signals substrate replacement.

Buying in Singapore

ADA Aquasoil Amazonia is stocked at Green Chapter, Fish Planet and several Thomson aquatic shops. Expect $35-$45 per 9-litre bag. Power Sand Special M sits around $50 per 6-litre bag. A 60 cm scape typically uses 18 litres of Aquasoil plus 3 litres of Power Sand.

Related Reading

Best Aquarium Aquasoil Comparison
How to Fix New Aquasoil Ammonia Spike
ADA Fertiliser System Guide
How to Choose Aquarium Substrate
Best Substrate for Planted Aquariums