I am a budget minded person so buying plant substrate for a 75 gallon tank could easily cost 150 $ Looking on the internet:
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- For the bottom layer mix potting vermiculite (from any nursury) with enough water to wet the vermiculite well but not so much that it floats. Squeeze and knead the vermiculite to get as much air out of it as possible, and also to separate the different layers of the vermiculite granules, making the mixture as fine as possible. When your hands look like they're covered in gold dust, you're done. Now add some soil that you have dug from outside (garden topsoil). See the suggestions for soils at the end of this section. You should mix in enough of this to turn the vermiculite from its shimmery golden color to grey. For example, I used about two gallons of Yolo loam with enough vermiculite to make a 3-inch layer in a 55 gallon tank, or about a quart mixed with enough vermiculite to make a 1.5-inch layer in a 10 gallon tank. The precise amounts are not important. After mixing in the soil, the mixture should no longer be runny with water. If it is, your tank will be quite cloudy when you add the water to fill it, so add more soil and vermiculite until it is no longer runny with water, but comparable to prepared cake mix before you cook it. This bottom layer forms a rich, soft medium for roots to penetrate into and obtain nutrients from. This layer should be as thick as possible, within aesthetic limits.
- The top layer is simply sand. You need about a 1 inch or more layer, simply to keep the lower layer from clouding the water. The best is #3 sandblasting grit, which our local gravel yard sells in 100 lb. bags for $10. Any sand that is not from the sea and is not too fine will do. #3 sand is about 2 mm in diameter. Just pour it on top, and level it out. Wash it first if you think it needs it. This layer should be at least 1" thick, and not more than 2".
erv:
