Aqua Soil (ADA Amazonia, Tropica, Controsoil)
Pros: nutrient-rich, lowers pH and softens water (good for South American fish), excellent root growth.
Cons: $30–80 per 9L bag, ammonia leach for first 2 weeks (cycle without fish), turns to mud after 2–3 years and needs replacement.
Best for: high-tech tanks, blackwater setups, demanding plant species.
Dirted (Walstad)
Pros: cheap (free if you have potting soil), lasts 5+ years, deepest nutrient reserve.
Cons: setup is messy, requires mineralization, ammonia spike during first 4–6 weeks, water can stay cloudy for first month.
Best for: low-tech tanks, no-CO2 setups, hobbyists comfortable with experimentation.
Capped Inert Sand or Gravel
Pros: cheap, neutral chemistry, easy to vacuum, no setup hassle.
Cons: zero nutrients — must use root tabs and liquid ferts.
Best for: budget tanks, hardy plants (anubias, java fern, crypts), tanks where you want flexibility.
Pool Filter Sand (PFS)
Pros: very fine grain, matches natural environments, $10 per 50lb bag.
Cons: no nutrients, can compact and create anaerobic pockets if too deep.
Best for: cory cats, small fish, blackwater tanks, root-feeding plants with root tabs.
Hybrid Approach
Many low-tech keepers use: 1 inch of laterite or aquarium clay (iron source) under 2 inches of inert sand. Cheaper than aqua soil, longer-lasting, supports root feeders well.