Substrate Volume Estimator
Substrate Volume Estimator calculates exactly how much substrate you need by volume and weight — supports sloped layouts and gives bag counts per type.
Calculator
ADA Aqua Soil
Premium nutrient-rich soil — ideal for high-tech planted tanks
Fluval Stratum
Volcanic soil granules — great for shrimp and planted tanks
Generic plant soil
Nutrient-rich baked substrate — budget-friendly planted tank option
Fine sand
Inert substrate — good for bottom-dwellers, pairs well with root tabs
Coarse gravel
Inert substrate — good water flow, easy to vacuum
Seachem Fluorite
Porous clay substrate — releases minerals, suitable for planted tanks
Dimension unit
Tank dimensions
Use internal tank dimensions, not external
Depth layout
Enter your values above to see results
Substrates for planted tanks
Tried-and-tested options across price points.
Lightweight volcanic substrate — promotes slightly acidic pH, good for demanding plants and shrimp
Nutrient-rich professional substrate — reduces the need for root tabs in most planted setups
Natural fine sand for aquascaping — inert, smooth texture, pairs well with root tabs
I’ve used everything listed in my own tanks. If you buy through a link, I earn a small commission — at no extra cost to you, and it never affects what I recommend.
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Frequently Asked Questions
- How deep should aquarium substrate be for a planted tank?
- For planted tanks, a minimum of 6–8 cm is recommended to allow roots to anchor and access nutrients. Smaller foreground plants like Eleocharis (hairgrass) or Marsilea can manage in 4–5 cm, but larger stem plants, Echinodorus (swords), and Cryptocorynes develop much better with 7–10 cm of substrate. For a sloped layout, the front can be as shallow as 2–3 cm (foreground) while the back is typically 8–12 cm. Inert substrates like sand or gravel can be shallower if you use root tabs to supply nutrients.
- How much does aquarium substrate weigh?
- Weight varies significantly by substrate type. Inert substrates like sand and gravel are heavy: fine sand weighs around 1.5 kg per litre, coarse gravel around 1.6 kg per litre. Nutrient-rich soils are lighter because they are porous and lower density: ADA Aqua Soil weighs around 0.9 kg per litre, and Fluval Stratum around 1.0 kg per litre. This means a high-tech planted tank using ADA Aqua Soil will have a lighter substrate load than the same tank filled with gravel — an important consideration for cabinet weight limits.
- Is ADA Aqua Soil better than gravel for planted tanks?
- ADA Aqua Soil and similar nutrient-rich substrates offer two advantages over plain gravel: they contain nutrients that feed plant roots directly, and they buffer the water to a slightly acidic pH (around 6.5–6.8), which is ideal for most aquatic plants and soft-water species. The downsides are cost (significantly more expensive than gravel), a limited lifespan of 2–4 years before nutrients deplete, and an initial ammonia leach that requires cycling the tank thoroughly before adding livestock. Gravel is inert and indefinitely reusable, but requires root tabs or liquid fertiliser to support heavy plant growth.
- What is a sloped substrate layout?
- A sloped substrate layout uses a shallow substrate depth at the front of the tank (typically 2–3 cm) that gradually increases toward the back (typically 8–12 cm). This creates a natural-looking aquascape that mimics the topography of riverbeds and hillsides, and also gives the viewer a sense of depth — the eye is drawn toward the taller background. Practically, it places most substrate where background and midground plants need it for root development, while keeping the foreground clean and uncluttered. The Iwagumi and nature aquarium styles popularised by Takashi Amano almost always use a sloped substrate.
- How many bags of ADA Aqua Soil do I need?
- The number of bags depends on your tank size and desired depth. Calculate your substrate volume in litres (length × width × depth in cm, divided by 1000), then divide by the bag volume — ADA Aqua Soil comes in 3L and 9L bags. For a sloped layout, use the average of front and back depths. Always buy at least one extra bag: substrate settles by 10–15% as it compacts over the first few weeks, and having spare substrate lets you top up without disrupting plants that have already rooted.