Do It Yourself DIY Mineralized Soil Substrate

DIY MINERALIZED SOIL SUBSTRATE

I’ve composed a list of materials and step-by-step instructions for those readers who would like to try the mineralized soil substrate method.

Materials Needed

• Cheap topsoil
• Pottery clay
• Dolomite
• Muriate of potash
• Fine gravel or coarse sand
• Large container for soaking soil
• Screen made from scrap wood and chicken wire
• Nylon screening material
• Large plastic tarp


Step 1 – Purchase and Rinse the Topsoil

Open the bag of topsoil and distribute in the container of your choice for soaking purposes. I use large Rubbermaid containers that are readily available from any mega-mart. You will want to use cheap topsoil and not potting soil. Potting soil has additives to avoid such as fertilizers, vermiculite and peat moss.
Fill the tub with water so the water level is a few inches above the top of the soil. I like to stir it around a bit to help break up any big clumps and evenly distribute the water. Let this soak for a day or two. Come back and slowly dump the water off of the top. Now add in more water so the soil is well covered. This water changing process helps to “rinse” the soil of any possible fertilizers or other harmful water soluble chemicals.

Step 2 – Allow the Topsoil to Dry

Pour the excess water out of the container as you did when changing the water. Lay out the large plastic tarp, preferably in direct sunlight. Dump out the muddy soil and spread it relatively thin over the tarp. Allow the soil to dry completely. This can take a day or two and depends greatly on how warm the temperature is where you are drying the soil. This part of the process could be done indoors. Though due to its messy nature, I suggest doing it outdoors if possible. When the soil is completely dry, add it back into the soaking container.
The drying process is the part that allows the microbes in the soil to begin mineralizing the nutrients. Exposing it to air oxygenates the soil.

Step 3 – Repeat the Rinsing and Drying Cycles

Repeat steps 1 and 2 three to four times. Repeating the steps is necessary to further mineralize the soil and remove any lingering fertilizers. The soil mineralizes the most during the time while it is still moist and exposed to air on the large tarp. By soaking it over again we reintroduce the needed moisture for this process to take place. When the soil is near fully mineralized it will have a very grainy texture. Another way to tell that the soil is ready is by smell. There will be virtually no smell coming from the soil once it is mineralized.

Step 4 (optional) – Sift the Soil to Remove Debris

Screening the soil can help to remove any large organic materials that the short mineralization process employed thus far cannot remove. I have setup tanks where I skipped Step 4 and others where I used it. I have found that adding this step to the process helps to further eliminate algae issues after a tank is newly setup.
You can use a wooden frame with chicken wire stapled to four sides. Then place nylon screening material overtop. Place a few handfuls of soil on top and gently push the soil across the surface of the screen. Make sure to put a container underneath to catch the sifted soil. Below is a picture of the sticks, leaves and stones that can be removed during this step. The resulting sifted soil will feel like airy sand.

Step 5 – Add the Clay

Now that you have a mineralized soil to use as the substrate, you will want to add in the aforementioned clay. Estimate how much clay you will need so that the resulting mixture of soil and clay is about 5% to 10% clay. If you prefer measurements I use about ¼ of a pound of clay per square foot of tank bottom.
To add the clay you soak it in a container of water to help emulsify it and make it easier to incorporate into the soil. A second option to add clay is to dry the clay in the open air and then crush it into a powder and add it to the soil. In either case you will want to eventually add enough water to the mixture to form a nice runny mud.

Step 6 (optional) – Create an Aesthetic Border

Now comes the fun part of setting up the aquarium. Add the gravel of your choice just along the front and side edges of the aquarium bottom. Wet it just enough that it holds a slope and press it up against the sides. Doing this step ensures that we will not see the different layers of substrate when viewing the tank from the front and sides. In this instance I have chosen to use 3M Colorquartz T-Grade Black Sand as a substrate top layer. I prefer this coarse sand for many reasons. It is very dense and holds a slope for a long period of time. The finer granules also allow for easy planting.

Step 7 – Add the Dolomite and Muriate of Potash

Sprinkle a light dusting of both the dolomite and muriate of potash on the bottom glass of the tank. The bottom of the glass should still be somewhat visible.

Step 8 – Add the Mineralized Mud

Fill in the borders you’ve created with the runny mud mixture of mineralized soil and clay. This layer should be anywhere from ½” to 1” deep.

Step 9 – Top With Gravel

Cover the mud with more of the same border gravel from step 6. If you skipped step 6 then simply cover over the mud with the gravel of your choice. Cover the mud by about 1” in the front to 2” in the back of the tank to create a nice sloping substrate effect.

Layer AddedStep 10 - Slowly Fill the Aquarium and Begin Planting

Begin planting and filling the aquarium as you would any other planted aquarium. Use caution when filling the tank with water. Go slowly to avoid disturbing the substrate and uncovering the soil.