Substrate or gravel is very important in a planted tank, you need enough depth so your plants can grow roots about 2 inches, you don't want large gravel, as roots may not grow properly, not too smaller substrate, it can be too heavy and crush the roots if the plants are in too deep, and you don't want sharp substrate or gravel if you want bottom dwelling fish.
So how do you choose a good substrate?
Well first you need to figure out what sort of plants, driftwood and fish colours you want, think about what colour substrate would amplify a fishes colour and make the plants stand out.
Generally a planted tank will use a fine grade silica sand. I chose a fine grade 0.8-1.4mm gravel substrate
You will need about 2 inches deep of substrate, use this calculator to determine how much you need.
Black substrate is affective at showing off brightly coloured fish. As you can see It does makes the tank look dark, but with some bright lights and bright green plants this can look quite stunning. - Personally I have used black midnight substrate.
White substrate really brightens up the tank, it is also use in Malawi themed tanks without plants(bottom)
Like in the Malawi tank a dark background can also help your fish stand out.
What about substrate Fertilization?
Aquatic plants need Micro and Macro Nutrients to grow. Many plants however will only require sufficient light, and CO2, but when starting out a fresh planted tank to get this going quickly, it is recommended that you use some sort of fertilizer.
- Rule out liquid fertilizer as it will encourage algae, as algae doesn't have roots.
- Fertilizer tablets are a good option, they can be placed under the substrate next to each of your larger stem plants, clay can also be used as a DIY option.
- Alternately you could start with your first layer of substrate organic top soil(ammonia free) approximately 1 inch deep then add your substrate another 1 inch on top of that. Check your LFS(Local Fish Store) some stores will sell fertile substrates.
