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Choosing a substrate for your aquarium is more than just picking a pretty color. According to Nic Tiemens, co-founder of Infinity Aquarium Design, you want to ensure the substrate won't adversely impact the water's pH, whether it's fresh or saltwater. You also want to ensure the substrate is clean or can be thoroughly clean by selecting a substrate that comes in a package rather than off the beach. Add in plants to the mix, and you want to be extra selective with your substrate.
Plants have root structures, so they need a substrate that roots can establish themselves and thrive in says Tiemens. "They also need substrates with minerals and nutrients," he says. "There's a wide variety of different substrates that will provide those nutrients to plants, and you want to make sure that you have one that is specifically geared towards a planted aquarium."
Whether you're designing your first aquarium or upgrading to one with plants, here are the best substrates to ensure a plant-friendly environment.
Best Overall: CaribSea Eco-Complete Planted Aquarium Substrate 20-lb bag
Eco-Complete has become one of the most popular substrates for freshwater live planted aquariums. It is composed of an extremely porous material that contains a wealth of nutrients as well as beneficial bacteria to support the nitrogen cycle. Among the key nutrients are iron, calcium, magnesium, potassium, and sulfur as well as two dozen other elements. These nutrients support robust root growth, while also promoting the development of healthy biologicals.
No rinsing of the product is needed—it can be used as is in your aquarium. Eco-Complete is nitrate and carbonate free, and thus will not impact pH or carbonate hardness. This formula can be used as the sole substrate, eliminating the need for a layer of laterite as well as a regular substrate over it. It comes in two different colors (black and red), and they don't contain artificial dyes, chemicals, or paints. Sold in a 20-pound bag.
Runner-Up, Best Overall: Seachem Flourite 15.4 lbs
Seachem Flourite is a porous clay substrate that is nutrient rich, particularly in iron. It can be used as a stand-alone substrate in a freshwater aquarium without the need for additional plant nutrients supplements. It is not chemically treated and is pH neutral. Seachem Flourite comes in 15-pound bags and is available in a natural dark color, red, black, and black sand.
Best for Live-Planted Aquariums: Fluval Plant and Shrimp Stratum
Fluval Plant Stratum is a lightweight porous substrate intended for use in freshwater live planted aquariums. It is formulated to support nitrifying bacteria and maintain a neutral to slightly acid pH while not discoloring the water. It will not compact and allows roots to grow and spread readily throughout the substrate. A variation of this substrate is made specifically for shrimp tanks. The color is designed to camouflage newborn shrimp from fish, and the grain size is small enough for them to hide in. This substrate is not recommended for large or boisterous fish, such as large cichlids or goldfish, nor is it intended for use in brackish tanks.
Fluval Plant Stratum, should be lightly rinsed to remove loose dust. The tank will initially be cloudy; however, it is safe for fish and shrimp even during the cloud stage, and will clear in a matter of hours. It is not recommended to mix this substrate with gravel or other substrates. Fluval Plant Stratum comes packaged in 4.4-, 8.8- and 17.6-pound bags. A single 4.4-pound bag is suitable for tanks under 18 inches, while an 8.8-pound bag is suitable for 18-inch tanks, and the 17.6-pound bag will cover a 24-inch aquarium.
Best for Nitrification: Activ-Flora Lake Gems for Aquarium, 20-Pound
ActivFlora™ Planted Aquarium Substrates are specialized gravels that contain essential minerals, micro-nutrients, and heterotrophic bacteria to support healthy nitrification processes. It can be used as the sole substrate and is pH neutral. Available in several grain sizes and colors for use in a variety of applications.
Our top pick of substrate for plants in a freshwater aquarium is CaribSea Eco-Complete (view at Amazon).
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This article was written by Shirlie Sharpe, is a fish and aquarium expert who has written a book on setting up an aquarium
For additional background on aquarium plant substrates, we spoke to Nic Tiemens, co-founder of Infinity Aquarium Design, who spoke about what to look for in substrates.