Gravel and sand don’t suit everybody, with certain aquarium residents, especially plants, preferring something a bit more silty. With the right reparation, you can make your own aquarium soil. Unless you want a tank full of beetle larvae and bacteria, don’t use soil straight from your garden.
Either collect garden soil using a trowel and bucket or buy a bag of potting compost from the garden. If you decide on the former, which is certainly cost-effective, only use soil from areas that have been chemical-free for a long time. If you use the latter, pick a bag marked “organic” or “chemical-free” and avoid peat, which makes water very acidic.
Sift the soil to remove stones, twigs, creatures and other debris. Sift enough to create a layer an inch or two deep in your aquarium.
Transfer the sifted soil to a baking tray and bake it at about 200 degrees Fahrenheit for 20 minutes. This sterilizes the soil, killing all the lurking microorganisms, seeds and other undesirable residents.
Lay the soil on the floor of your tank. Even a thin layer should help support your aquarium plants.
Pour a layer of gravel or sand over the top. This prevents the soil being stirred up and turning your lovely aquarium into a tankful of mud. Plant roots will be able to reach the soil and the nutrients it contains.
Add water to the tank slowly. It might be helpful to pour it down the sides to avoid stirring the substrate. Cycle the aquarium as you would any other fish tank.
- Soil affects the chemistry of your tank. If you plan to keep very sensitive fish, test the pH of your aquarium after cycling. If it is too acid or too alkaline for the species in question, either don’t keep those fish or start again using only sand or gravel.
- Some chemicals linger in ground soil for years. If you’ve recently moved into your property or didn’t garden organically, don’t use garden soil. It is cheaper to pay a few dollars for potting compost than to replace dead fish.
- Soil is great for some plants. It is also great for algae, for the same reason: It is packed with nutrients. Be prepared for a lot of algae, both free-floating and covering surfaces, especially in the beginning.
Judith Willson has been writing since 2009, specializing in environmental and scientific topics. She has written content for school websites and worked for a Glasgow newspaper. Willson has a Master of Arts in English from the University of Aberdeen, Scotland.