This is highly dependent on which aquatic plants we’re talking about. Some plants can grow just floating in the water column, some can grow on things like rocks and pieces of wood, while others must have substrate to grow.
Knowing which plants you’d like to incorporate into your aquarium is one of the first things to consider when assembling your planted tank. This decision will essentially determine the overall look of your tank and may act as your foundation…literally.
In this post, we’ll go over a few different ways that certain species of aquatic plants can grow.
Plants that can grow just floating around your tank, without the need for a substrate layer. These include most mosses such as Java Moss or Christmas Moss they can also be grown by tying them onto rocks or a piece of wood.
Some examples of non-moss species; Amazon frogbit, Water Lettuce, Marimo Moss Ball and Hornwort however, unlike the moss, these cannot be tied down. When choosing these types of floaters you must take into consideration the possibility that they may block light from reaching the plants below them, which may cause some loss of plants.
Plants requiring some form of anchor
Anchoring plants simply require something to hold onto, typical anchors are rocks and driftwood. These species typically have few large roots and need to be tied to an anchor during it’s initial placement. Over time, these plants will have rooted themselves on the anchoring medium and will no longer need to be tied. Examples are Anubias Nana or Java Fern.
Plants that require at least a shallow substrate layer
For these plants you will need substrate that is at least 2 inches in depth, although they have been grown in less, this is a good place to start. Examples of these shallow growers are; Rotala Wallichii and Hygrophila
Plants that require a deep substrate layer
And finally, deep rooting aquarium plants such as Cryptocoryne Wendtii. The Cryptocoryne species are known simply as “Crypts”. These aquarium plants will need substrate of at least 2 and a half inches in depth.
While dosing with fertilizers is not necessary if you have , it’s important to note where your plants grow, will determine how you dose your fertilizers. For free floating aquarium plants and anchored plants you will want to use liquid fertilizers such as NilocG Aquatics Thrive All In One Liquid Fertilizer. The reason is that they rely on the water column for there nutrients.
For the species that are planted within the substrate, Seachem Root Tabs are suggested but liquid fertilizers can also be used.
Choose your plants first then determine how the plant likes to grow. This will ultimately answer the question “Do you need substrate for aquarium plants?”. As you’ve seen above, the answer is technically no and technically yes.
Until next time, keep your thumbs aquatic!