{"id":297,"date":"2021-11-18T03:52:24","date_gmt":"2021-11-18T03:52:24","guid":{"rendered":"https:\/\/rootedtank.com\/?p=297"},"modified":"2023-07-18T01:02:31","modified_gmt":"2023-07-18T01:02:31","slug":"planted-tank-substrate","status":"publish","type":"post","link":"https:\/\/rootedtank.com\/planted-tank-substrate\/","title":{"rendered":"Comprehensive Substrate Guide For Planted Tanks"},"content":{"rendered":"\n

Substrates are one of the most important factors for growing and sustaining healthy aquatic plants. The following article will be one of the most comprehensive explorations into the role aquarium substrates play in the fishkeeping hobby, what types are available, and how to choose a substrate that’s best for your tank.<\/p>\n\n\n\n

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What is substrate?<\/h2>\n\n\n\n

Substrate is the bed of gravel, sand or soil that lays at the bottom of an aquarium. It’s where aquatic plants grow roots and obtain some of their nourishment from.<\/p>\n\n\n\n

\"What<\/figure>\n\n\n\n

What is substrate made of?<\/h2>\n\n\n\n

Aquarium substrate can be made of gravel, clay, sand, dirt, crushed shells and other artificial and organic materials. Each material type has advantages and disadvantages for growing plants.<\/p>\n\n\n\n

\"Different
Different types of substrates<\/figcaption><\/figure>\n\n\n\n

Why is substrate important for planted tanks?<\/h2>\n\n\n\n

Substrate affects how successfully plants can grow their root systems and absorb nutrients. Some demanding plants may benefit from having nutrient-rich active substrates. Others may benefit from substrates with a large grain size to allow for proper root expansion.<\/p>\n\n\n\n

Aquarium substrate also increases the available surface area in a tank for beneficial bacteria to grow. This is important for establishing a nitrogen cycle, especially if you have a large bio-load of livestock.<\/p>\n\n\n\n

Types of substrates<\/h2>\n\n\n\n

Substrates can be placed into two categories: inert and active. These terms refer to whether or not the substrate provides added nutritional value to plants.<\/p>\n\n\n\n

Inert substrates<\/h3>\n\n\n\n

Gravel, clay and sand are considered “inert” substrates because they do not add nutritional value to aquarium plants. Also, they do not affect a tank’s water chemistry, such as its pH and hardness.<\/p>\n\n\n\n

The term “inert” is defined as being chemically inactive.<\/p>\n\n\n\n

Active substrates<\/h3>\n\n\n\n

A substrate is considered “active” if it changes a tank’s water chemistry. Specifically, they contain macronutrients such as nitrogen, magnesium, potassium and phosphorus; and micronutrients such as iron, manganese, copper and zinc.<\/p>\n\n\n\n

Aqua soils<\/h4>\n\n\n\n

Aqua soils are a type of active aquarium substrate. They are designed specifically for promoting aquatic plant growth. This is achieved by reducing water hardness and pH or by leaching macro and micronutrients that plants consume.<\/p>\n\n\n\n

Crushed coral and aragonite<\/h4>\n\n\n\n

Crushed coral and aragonite<\/a> are another type of active substrate that release minerals into the water. These substrates are designed to increase KH<\/a>, GH and pH. These substrates are usually not used in a planted aquarium unless you live in a region that has naturally soft pH and hardness.<\/p>\n\n\n\n

Base layer substrates<\/h3>\n\n\n\n

Base layer substrates have larger grain sizes and increased porosity to allow for increased substrate water flow and oxygenation. They can also contain bacterial culture starters, which promote the grow of aerobic bacteria used in the nitrogen cycle.<\/p>\n\n\n\n

\"Substrate
Substrate base layer<\/figcaption><\/figure>\n\n\n\n

They are usually added at the bottom of the tank beneath a layer of another substrate, usually an aqua soil.<\/p>\n\n\n\n

The increased water flow and oxygen is possible because base layer substrates are much less compact than sand. This reduces the chances of anaerobic bacteria, which is unwanted bacteria that converts nitrate into nitrite (instead of the other way around).<\/p>\n\n\n\n

Other benefits include increased the lifespan of your substrate in aquariums that you want to last for multiple years at a time, and as a tool for aquascapers to create slopes and increase substrate height.<\/p>\n\n\n\n

Base layer substrates are a good practice, but not common for most aquarium keepers to use. They are recommended but not required.<\/p>\n\n\n\n

Dirt substrate<\/h3>\n\n\n\n

Aquarists can also use organic potting soil or mineralized top soil as nutrient-rich substrates. This method is recommended for advanced fishkeepers due some of the risks.<\/p>\n\n\n\n

\"Dirted
Dirted substrate<\/figcaption><\/figure>\n\n\n\n

Dirt is usually added as a base layer and capped with and equal thickness of sand or gravel. This cap needs to be compact enough to prevent the dirt layer from seeping into the water column, but coarse enough to allow for root growth.<\/p>\n\n\n\n

Therefore, a coarse sand or fine gravel top layer is recommended.<\/p>\n\n\n\n

Dirt has a very high level of nutrition, will promote explosive root growth, and is relatively inexpensive compared to aqua soils.<\/p>\n\n\n\n

The downside is that it’s incredibly messy and will cause very cloudy water if it’s disturbed in even a minor way. Also, it’s high nutrition value can cause algae blooms if it’s not properly balanced with appropriate lighting and CO2.<\/p>\n\n\n\n

It’s messiness also makes it difficult to replenish with root tabs.<\/p>\n\n\n\n

How many substrates do I need to use?<\/h2>\n\n\n\n

Layering or mixing an aqua soil with another active substrate will help plants achieve optimal growth. But it is also possible to achieve successful plant growth using single inert substrates if you supplement root tab fertilization<\/a>.<\/p>\n\n\n\n

Individual inert substrates<\/h3>\n\n\n\n

Inert substrates can be used on their own to successfully grow plants. However, their lack of porosity makes it difficult for plant roots to “grab a hold” of the substrate grains and grow robust root systems.<\/p>\n\n\n\n

Also, they do not add macro or micronutrients into the water. This doesn’t hurt plants, but it doesn’t benefit them either.<\/p>\n\n\n\n

Lastly, inert substrates are unable to “hold” nutrients from the water column and feed them to plant roots. This is because they have no CEC value.<\/p>\n\n\n\n

If you choose to use just an individual inert substrate for your planted aquarium, it’s necessary to add root tabs every 3-5 weeks and dose liquid all-in-one fertilizer to ensure your plants get the nutrition they need.<\/p>\n\n\n\n

Individual aqua soils<\/h3>\n\n\n\n

Active aqua soil substrates can work well on their own because they have porosity, high CEC<\/a>, contain macro and micronutrients, and soften aquarium water. These properties create an optimal environment for plant growth.<\/p>\n\n\n\n

One drawback is that aqua soils are more expensive than inert substrates and other active substrates such as Seachem Flourite and CaribSea Eco-Complete.<\/p>\n\n\n\n

Mixed active substrates<\/h3>\n\n\n\n

Mixing active aqua soils with active non-aqua soils, such as Seachem Flourite or CaribSea Eco-Complete, is an effective and easy method for increasing your substrate’s volume in an inexpensive way.<\/p>\n\n\n\n

This method involves simply mixing the two substrates together before adding them to your aquarium.<\/p>\n\n\n\n

Although they are technically considered active substrates, Flourite and Eco-Complete do not drastically affect the pH or hardness of aquarium water. Nor do they contain large amounts of macro and micronutrients.<\/p>\n\n\n\n

Layered active substrates<\/h3>\n\n\n\n

An effective, and nice-looking, method is to layer two or more active substrates on top of one another. For example, you may choose to add a 1-inch layer of aqua soil on the bottom, followed by a 1-inch layer of an active non-aqua soil like Eco-Complete, followed by a 1-inch layer of aqua soil on top.<\/p>\n\n\n\n

This method is similar to the “mixed” method above, but may allow for greater water flow and oxygenation in the middle layer. Also, the nutrient-rich base layer may benefit heavy root feeders such as cryptocorynes and Amazon swords.<\/p>\n\n\n\n

Do substrates change water parameters?<\/h2>\n\n\n\n

Some active soil substrates are designed to reduce an aquarium’s pH with peat moss. Certain substrates may also leach ammonia into the tank, which is an important macronutrient for plant growth, but is harmful to livestock if there is no bacteria that detoxifies it.<\/p>\n\n\n\n

Substrate<\/strong><\/td>Lowers pH<\/strong><\/td>Leaches ammonia<\/strong><\/td>Contains other nutrients<\/strong><\/td><\/tr>
Sand<\/td>No<\/td>No<\/td>No<\/td><\/tr>
Gravel<\/td>No<\/td>No<\/td>No<\/td><\/tr>
Seachem Flourite<\/td>No<\/td>No<\/td> No<\/td><\/tr>
CaribSea Eco-Complete<\/td>No<\/td>No<\/td>Yes<\/td><\/tr>
ADA Amazonia<\/td>Yes<\/td>Yes<\/td>Yes<\/td><\/tr>
Fluval Stratum<\/td>Yes<\/td>Yes<\/td>Yes<\/td><\/tr>
Tropica Aquarium Soil<\/td>Yes<\/td>Yes<\/td>Yes<\/td><\/tr>
Mr. Aqua Aquarium Soil<\/td>Yes<\/td>Yes<\/td>Yes<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n

The reason some substrates reduce pH is because most aquatic plants thrive in slightly acidic water. Somewhere between 6.0-7.5 pH is ideal for most plants<\/a>.<\/p>\n\n\n\n

\"7.2
7.2 pH<\/figcaption><\/figure>\n\n\n\n

This is because all important macro and micronutrients are water soluble in this range. When pH gets to around 8.0 or higher, some nutrients are unable to dissolve in water, which means they can be absorbed by plants.<\/p>\n\n\n\n

Substrates that contain peat<\/h3>\n\n\n\n

The following substrates contain peat. This is what allows them to soften water by reducing KH and pH.<\/p>\n\n\n\n