Growing Plants Under Low, Medium or High Tech Conditions

|   The Terms of Which Our Hobby Has Defined How We Grow Aquatic Plants is Often Convoluted and Confusing. In This Article, We Hope to Clarify the Elements That Defines Which…

The terms of which our hobby has defined how we grow aquatic plants is often convoluted and confusing. In this article, we hope to clarify the elements that defines which level or degree of technologically advanced methods of aquatic gardening is utilized.

Perhaps the most common question asked is “which is better?” To best answer that question, we will break down the components required for aquatic gardening into basic needs, in human-terms; food, shelter, and clothing.


First and foremost, plants need food to flourish. When thinking about the structure of most plants, they generally have leaves on the upper portion which act like lungs, and roots below which play the role of the mouth. Both draw in nourishment to some degree, but for completely different functions. A plants root structure draws in nutrients from the soil. When you add root tabs directly to the soil, like Seachem Flourish Tabs, you are providing nourishment directly to the substrate for the plant. When adding liquid fertilizers, the liquid is just a means of delivering, or transporting the dissolved fertilizer. The heavy minerals in the solution make their way into the soil. For this reason, you should ensure your liquid fertilizers are thoroughly mixed prior to adding them. Seachem added the AquaVitro lineup to their offering several years ago, which now includes a complete product line for aquascapers and enthusiasts, intended to compete with ADA products. Their Flourish products remain geared towards the general hobbyist. Something both hobbyists and local shops should consider is that AquaVitro products are only sold in stores. We like this marketing strategy very much, as it supports our LFS.

Another form of feeding comes in the form of breathing or photosynthesis, a process by which green plants and some other organisms use sunlight to synthesize foods from carbon dioxide and water. Photosynthesis in plants generally involves the green pigment chlorophyll and generates oxygen as a byproduct.


Low tech: A 2-quart soda bottle of water, sugar and yeast, and vinyl air line fed into a canister filter or powerhead intake. There are several homemade options available for obtaining a general idea as to how much CO2 you are supplying but a low tech configuration will lack precision.

Medium tech: A combo regulator-solenoid metering valve, or a regulator plus a metal metering valve, ultra gas tubing and a homemade “reactor” made from a gravel vacuum sleeve (or just insert the carbon dioxide tubing into the intake of a powerhead or canister filter). Once your regulator and metering valve are properly adjusted, you generally do not have to fiddle with them much.

High tech: A two-stage, high-precision, specialty gas regulator with a built-in 4-micron filter (a micron is a measurement of the smallest size particle that the filter will pass; 1 micron = one-thousandth of a millimeter) and stainless steel diaphragms with factory calibration, a vernier scale 500-turns-per-inch gas flow metering valve (a vernier scale is made to slide or rotate along the division of another graduated scale for indicating parts of divisions), a higher-cost pH controller, a solenoid plus one-quarter-inch copper tubing and brass fittings, and a reverse flow external carbon dioxide reactor. This equipment is easy to adjust and maintains a remarkably stable flow of carbon dioxide.

A solenoid on a timer can save you some carbon dioxide when the lights are off. You can also just run the carbon dioxide all day, every day Whichever you choose, the changes in pH will not be important. In any case, aquatic plants do not care where the carbon dioxide comes from.

If one is not quite ready for the initial investment in a CO2 injection system, but would still like to enjoy some of the benefits of adding additional carbon, there is an alternative. Flourish Excel, another great product by Seachem, provides a simple organic carbon molecule that plants can use as a building block for more complex carbohydrates. Because Flourish Excel is an organic carbon source it does not impact pH.

Another option to consider is the use of emergent or bog plants in an aquatic terrarium environment. Aquatic terrariums, also referred to as paludariums, are  semi-aquatic enclosures simulating a rain forest, swamp or other wetland environment. It also can be seen as an aquarium interconnected with a terrarium, having both the underwater area as well as the shore. Emergent plants are ones which begin their life underwater and grow so tall, to the point that the top-most portion grows out of the water. Bog plants follow a similar path, but most of the plant exists above the waterline. In both cases, since the carbon exchange takes place above the waterline, no additional CO2 is required.


Low tech: Placement of the aquarium near a window where it can receive sunlight and/or basic T5 lighting that generally comes as a kit with the aquarium.

Medium tech: A multi-T5 or T5HO fixture with 10,000K and 6,700K bulbs, or full-spectrum units like the Sunblaster from Future Harvest Development rated for hydroponics use.

High tech: A precision-tuned, high-density lighting set with varying spectrum LEDs with or without additional full-spectrum T5HO lighting.



When we think of shelter, we generally think of some walls and a roof, but in reality, it is the benefits of that shelter that we seek out, much the same as plants do, including protection and warmth. Plants, much like fish, have certain requirements that must be met in order for them, not only to survive, but to thrive.


Low tech: Placement of the aquarium near a sunny window or in a warm room. This is a fine option for temperate setups, especially if the fish are tolerant of widely fluctuating temperatures.

Medium tech: Conventional tube-type heater, often made of glass, or in-line heaters. These types of heaters are an easy and economical way to maintain a regulated water temperature for planted, tropical environments. Some of the best conventional heaters on the market are made by EHEIM.

High tech: The use of substrate cable heaters are often viewed as a natural approach. The idea is that the Earth is hotter at the core and cooler on at the surface. Substrate cable heaters, in conjunction with a deep substrate bed, simulate this. However, being that there has been no special benefit to the aquatic plants or fish having substrate heating cables in a planted aquarium, most opt for the medium-tech approach.


When we think of clothing, we think of what covers us. In this case, it is the substrate. There are a multitude of options available when it comes to selecting a substrate for use in a planted aquarium. Some have inherent benefits like being chocked full of certain beneficial minerals, while others feature exceptional retention a attributes, acting as sponges, absorbing any minerals added. Red clay for example, is red because it contains iron (Fe2O3). If you have red plants, opting for a substrate rich in iron could be a great idea. You can also chose to layer your substrate, and adding a top layer for aesthetics.


Low tech: Dechlorinated tap water. Sodium Thiosulfate (Na2S2O3) is the active ingredient in dechlorinator, which turns the Chlorine into Chloride ions by breaking the Cl-Cl bond. With Chloramine you get two Chloride ions and Ammonia.

Medium tech: A mix of RO (reverse osmosis) water purchased from your local aquatic shop, and dechlorinated tap water.

High tech: An in-home/office water system from a manufacturer, like locally owned/operated AquaFX, that produces 50-300 gallons of pure, zero-TDS (total dissolved solids) RO or RO/DI (reverse osmosis / de-ionized) water per day. There is no residual trace of Chlorine, Chloramine, Ammonia, or Chloride ions left in the water.

In terms of humans, water is a necessity for ingestion to sustain life. In the aquarium, it creates the surrounding environment. Tap water has an awful lot of impurities in it, including chemicals and chemical by-products that remain in the water as a result of the treatment process. Many of the chemicals used, have no suitable purpose in the planted tank, or even in an aquarium stocked with fish.


Low tech: Backyard dirt topped with some “ready mix” gravel from the lawn and garden center.

Medium tech: A bag of baseball infield gravel; or ordinary aquarium gravel or river sand that isn’t too finely grained, with a build-up of mulm (the fine organic leftovers of aquarium detritus). Ordinary sand or gravel will also work once the mulm builds up and provides “natural” enrichment. You can add some sphagnum peat moss as an underlayment to help get the substrate enriched at the start.

High tech: Calcined fractured natural clay substrate with an underlayment of commercially processed laterite (i.e. more clay) or nutrient-enriched manufactured porous gravel. The commercial natural clay and manufactured substrates offer some visually pleasing choices. These substrates are robust growing media right from the start.

If the substrate is too fine, it can become impacted, developing pockets of anaerobic bacteria. If the granules are too large, too much detritus can become embedded between the stones, and it can be hard to keep aquatic plants rooted. A substrate with grains about 2 to 3 millimeters in size works well.

Soil underlayments, or “dirt bottoms”, work well if you keep the lighting moderate to low: about 1 ½ to 2 watts per gallon of twin-tube compact fluorescent lighting with high-quality reflectors. The dirt can steadily provide years of nutrients that slower-growing aquatic plants require. An added benefit is that because the dirt will develop some anaerobic activity, it will also produce a small amount of carbon dioxide. Fast-growing aquatic plants will do better if some macro-nutrients (nitrogen, potassium and phosphate) are added to the water.

Dirted aquariums are a particular style of planted aquarium, pioneered by Diana Walstad in her book Ecology of the Planted Aquarium. The main benefits are that it is relatively inexpensive, simple, and because it is a slow growing method, the maintenance is low. On the other hand, it can be hard to keep the dirt out of the water when you uproot aquatic plants. Fast-growing plants can appear stunted without additional fertilizer, and the stronger aquatic plants will tend to dominate the aquarium over time without proper pruning.

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