In this addition of the Planted Aquarium Care series, I’ll talk about substrate – the pebbles, gravel, or sand at the bottom of your aquarium – and how your choice of substrate significantly affects the wellbeing of your plants. In particular, I’ll explain why the health of your plants’ roots is affected by the quality of your aquarium substrate.

First, a Very Brief Overview of How Plants Transport Food:

Apart from moss, all true plants, including ones for the aquarium hobby, transport nutrients internally by way of a vascular system – one composed of xylem and phloem. Notice the distinct sections of xylem and phloem in the below cross-section of a plant root.

While the phloem transports most notably sucrose produced during photosynthesis mainly in the leaves down throughout the rest of the plant, the xylem transports water and soluble mineral nutrients (ones absorbed by the roots) upwards and throughout the plant. Hence, the plant leaves and roots are co-dependent upon one another: The leaves provide the plant (including the roots) with sucrose, while the roots provide the plant (including the leaves) with water and mineral nutrients.

So, why am I telling you this?

Well, because of the particular function of the xylem, the health of plant roots is absolutely vital for the wellbeing of the plant as a whole. After all, the roots absorb the nourishing water and minerals that the xylem transports throughout the plant. Hence, in addition to adequate lighting, a healthy and full root system makes for green, vibrant, and full foliage.

And that’s exactly why choosing the right substrate for your planted aquarium is so important.

Before I discuss why grain size affects the health of roots let me make this one point: Aquarium plant roots are extremely delicate!

You may think that this is not the case when witnessing an aquarium shop seller tear through the thick jumble of roots in order to remove the plant from its home at the aquarium shop. But, keep in mind that those most visible thick roots you see are the primary roots – roots which are hardly responsible for water and nutrient absorption!

In fact, it is the secondary roots (also termed lateral roots), which sprout from the sides of the thick primary roots, that are responsible for the majority of nutrient uptake. And, these secondary roots are much, much thinner than their primary counterparts and are far more delicate.

Substrate Grain Size Makes a Difference.

Since the secondary roots which significantly contribute to the health of the plant are extremely delicate, they are very susceptible to physical damage – to damage caused not only by the plant’s physical removal from the pet shop aquarium, but also by the shifting of large sized pebbles in the home aquarium substrate.

For this reason, I feel that the smaller the grain size of the aquarium gravel, the healthier the root system will be. Indeed, very fine gravel and sand shifts significantly less than does large grained gravel and pebbles.

Especially when using a gravel vacuum (by the way, you should gravel vac areas around plants only VERY gently), large grained substrate moves around a whole lot …even in the areas of the aquarium that are not being gravel vacuumed.

Imagine the damaged sustained by the secondary roots when pummeled and pulled by a 2 inch deep and tumbling layer of large pebbles! Now fathom the plant roots having to suffer this abuse on a continuous weekly or biweekly basis (and, even when you’re not gravel vacuuming your aquarium, large grained substrate does tend to shift)!

That said, how in the world can you expect the secondary roots to keep up with the sustained physical damage, and, consequently, why would you expect the roots to support a full foliage if you place the plant in large grained substrate?

The good news is that you can easily alleviate the above mentioned problem by simply using fine grained gravel, or even sand (intended for freshwater aquarium use), as opposed to bulky gravel or pebbles.

In fact, fine grained gravel not only provides your aquarium plant roots with a stable environment, but it also offers far more surface area for biological filtration and looks much nicer too.

From My Personal Experience:

When I switched over from regular sized gravel to sand in 2006, my aquarium plants displayed an explosion of growth! I witnessed a huge and visible benefit to the health of my plants literally within a week and a half! They grew to a much larger size, became fuller, and turned greener, and the only change I made was to replace the normal sized gravel with sand!

Although some of my readers may be concerned with the development of oxygen starved (anaerobic) zones within the deepest layers of the sand substrate, keep in mind that 1) I only keep the sand layer deep in the parts of the aquarium nearest to the plants, and that 2) the roots actively pull water through the substrate anyway.

In fact, after I added the sand to my aquarium, the plant roots expanded to such a great extent that even the thinnest layer of sand in the front of the aquarium is inhabited by a shockingly dense patchwork of roots.

So, if you want to take it one step further and add sand instead of fine gravel to your planted aquarium, I say go for it! Also, if you have any questions about my aquarium setup, feel free to post them in the comments section below.

Take care, and happy fish-keeping!

A quality lighting solution is needed because plants require light for the production of food and, without adequate illumination, they won’t be able to sustain normal growth. In other words, insufficient lighting results in malnourishment. Most aquarium plants shed old leaves on a regular basis, and malnourished plants are simpley not able to replace leaves lost with new foliage, resulting in an assortment of ever shrinking plants.

Generally, the more light your plants receive, the better they’ll do under your care. That said, there are a few aquarium plants that will do well under less than optimum lighting solutions. In fact, the ever growing multitude of aquarium plant species available to the hobby require varying amounts of light. Below, I will discuss some plant options for low light, medium light, and high light aquarium plants.

Low Light Plants

The most attractive and notable low light plants are the many Java Fern, Cryptocoryne (often called “Crypts”), and Anubias varieties and species. All three of these plants are a mainstay in the aquarium hobby, and all three are highly recommended for beginners. Anubias, in particular, is a very hardy and will do well under normal output fluorescent bulbs. Though Anubias grows slower than most other plant species, large specimens with broad leaves are readily available at most aquarium shops.

Medium Light Plants

Medium light plants will need compact fluorescent or, better yet, T5 fluorescent lights to do well in the home aquarium. Most Sword Plants (Including the popular Amazon Sword), Banana Plants, Wisteria, and Water Sprite are among the more popular medium light specimens available. All tend to grow to a larg size, and serve as excellent mid-ground to background plants.

High Light Plants

Surprisingly, many, if not most of the plants you’ll find at your local aquarium shop require a large amount of light supplied by multiple T5 bulbs or metal halide lights (for very tall aquariums).

Most of the plants sold as bunches (often tied by a rubber band and/or led weight) require an ample amount of light. In particular, Four Leaf Clover Plants, Dwarf Tears, Ludwiga, Moneywort, Myrio, and Rotala all need high light. Madagascar Lace and the Chain and Red Sword Plants will also do best under ample illumination.

Unfortunately, aquarium shops often keep high light plants under low light. As a result, many costumers either assume that these are low light plants, or are misinformed by ignorant sellers into believing that these plants will do well under normal output fluorescent bulbs. Just a week after taking home some Myrio or Rotala for example, misinformed customers are left with a fish tank full of withered plants, with Myrio that lacks its feathery foliage, and specimens of stemmy Rotala with heaps of decomposing leaves beneath their emaciated bodies.

My aim is not to terrify readers with images of doom. Instead, I am merely illustrating my point: keeping high light plants under normal output fluorescent bulbs is a recipe for failure. It is therefore essential to determine whether your aquarium setup will accommodate the needs of the plants you plan to keep.

Simply doing a little research prior to purchasing aquarium plants will go a long way. If your aquarium is illuminated by normal output fluorescent bulbs, some Anubias and Java Fern is a good choice. If, however, you’d like to add a Madagascar Lace accented by a carpet of Chain Swords in the foreground, you will have to invest in a more powerful lighting system (there is no way around it). And believe me, you won’t regret making the small investment in a T5 lighting fixture!

Also, keep in mind that adequate lighting is just a part of the equation. Clean water and the presence of CO2 and nutrients, including iron, are also essential for success with aquarium plants. I’ll discuss these issues in future Planted Aquarium Care 101 articles.

First, a quick introduction:

So, what is a planted aquarium anyway? What makes these aquariums different from other tropical fish tanks?

To put it very briefly, planted aquariums are ones that rely primarily on plants for aesthetic appeal. In other words, plants serve as the heart of the planted aquarium with tropical fish accenting and complementing the lush underwater garden.

For this reason, planted aquariums are specially made for providing plants with a suitable environment. Success with this planted type of aquarium, therefore, requires a bit of extra planning in order to ensure the health of your plants. Indeed, lighting quality, water-flow, substrate type, the variety and amount of tropical fish your aquarium sustains, and perhaps the addition of extra equipment are all issues to consider before setting up a new planted aquarium or converting an existing freshwater fish tank into an aquatic garden.

That said, the extra planning and input will go a long way. Moreover, both the presence of plants and the extra attention you’ll pay to maintaining optimum water conditions will significantly contribute to the health and vitality of you fish. Believe it or not, tropical fish and aquarium plants share many basic needs.

Lighting the Planted Aquarium

Like all plants, aquarium plants rely on photosynthesis for the production of food. They need light for nutrition and growth. Choosing suitable aquarium lights, therefore, seems like the natural starting point for planning a planted aquarium.

While regular tropical fish tanks will do well with normal output fluorescent lights, planted aquariums require a more heavy duty solution. That’s because normal output bulbs – the type used for household use and, unfortunately, for most aquarium “kits” and complete setups – produce a small amount of poor quality light.

In other words, the intensity of normal output fluorescent bulbs is not strong enough to sustain aquarium plant growth. These bulbs also tend to produce a reddish yellowish hued light that will stimulate algae growth, but won’t do wonders for your plants.

Fortunately, there are other lighting solutions for the planted aquarium. Metal halide bulbs work wonderfully. Nevertheless, they are both costly and expensive to operate (they’ll double your electricity bill!). Power compact fluorescent bulbs are also great and cost much less than their metal halide counterparts, but they’re still not the best way to go.

Instead, I highly recommend T5 fluorescent bulbs for planted aquariums.

T5’s are long lived, they produce a high quality of light, they pack more punch per Watt than other bulbs (excluding metal halides), they’re more compact than their normal output fluorescents (T12’s or T8’s, depending on where you live), and they don’t produce excessive heat! T5’s stay cool. They are by far the best lighting solution in the planted aquarium hobby.

With T5 bulbs, I suggest getting about 2 to 3 Watts per gallon. This arrangement will ensure that your aquarium plants will receive the sustenance they need to thrive under your care.

That’s it for this Planted Aquarium Care 101 post. In the next installment of the series, I’ll discuss plant varieties according to lighting needs: namely the so called low light, medium light, and high light aquatic plant categories.