Plants that grow in an aquarium need substrate; it’s as simple as that. They are not different from garden plants or any other plant for that matter. They need somewhere for their roots to stretch, grow, and uptake nutrients. Similar to mud, a freshwater substrate for live plants will provide planted aquariums with the nutrients it needs to flourish. This means that the material used must fulfill the conditions required by your selected plants or there could be dangerous obstacles that will arise down the road and cause your plant's health or growth to suffer.
Keeping the pH Just Right
Believe it or not, most plants can grow just fine in a variety of pH. In fact, having pH swings can be good for plants as the uptake of nutrients and minerals changes depending on the pH. Ideally, the pH should be kept between 5.0 and 7.2, with some slightly higher levels being acceptable for certain plant and shrimp species. This means that you should not add glass beads, colored ceramics or epoxy-coated gravel to the planted tank. You should also to stay clear of crushed coral and seashells; including them in the substrate mix will raise the water’s pH as they begin to break down over time. The key is to stick with natural materials and avoiding using anything synthetic.
The discussion about the ‘rights and wrongs’ of pH may have left you unnerved, but rest assured the correct water chemistry isn’t hard to find or maintain. If you want to understand the science behind it all, try reading Diana Walstad’s ‘Ecology of the Planted Aquarium.'
In the meantime look through the variety of natural substrates that are available in the market; two possibilities are ‘EcoComplete’ and ‘Fluorite Brown.' EcoComplete has a distinct effect; producing healthy, lush plants that will ‘take off’ in two to three weeks. Alternatively, you could try mixing laterite with number 20 red flint gravel; the color is eye-catching, and the plants love it! If you're going for a lot of root growing plants, having a soil which has nutrients in it is ideal. ADA Amazonia is a popular choice amongst planted tank owners. It is full of nutrients that will last a very long time in your tank.
Size And Depth Are Just As Important!
When adding a layer of substrate to the tank, make sure it is 3 to 8 mm thick. You will need to consider the plant’s root type to understand exactly how deep the substrate needs to be. The coarser the soil, the more aerobic activity will be happening. Using a soil that is too fine can cause the soil to become anaerobic and cause problems especially if stirred. If keeping delicate invertebrates such as shrimp, it is recommended to use a coarser substrate such as Akadama.
Here are 4 of the groups that you may come across;
If you have a variety of plants, try grading your substrate by adding an inch more to the back than the front.
In the end, using freshwater substrate for live plants is quite a complex process, but practice and research can simplify it a ton. You need to understand the type of plants you are adding and the properties of the water that you are using. But rest assured, if you do it right the results will make all the effort well worth it. After all, there is no gain without pain right?