top of page

3 Keys to Success in Planted Aquarium & common mistakes

Updated: Feb 1, 2023

The 3 Keys To Success... Quality Substrate, Good Lighting, Good Nutrition


The term Substrate refers to the medium that the plants will root in. Just like your house plants, what you "plant" them in can be very important because that is where many varieties of plants draw their nutrients from. When choosing your substrate you must consider the types of plants you are interested in growing and know their needs.


ere are a few varieties of plants that could care less what the roots are in because they get very little nutrition from the roots and only use their roots to anchor them whereas other aquatic plants rely heavily on the root systems and a quality substrate for nutrients. Later on I will list some varieties of plants that need a quality substrate and some that do not.

The most common mistake made by beginners is to get the cheapest gravel they can find and a month later we ask ourselves why the plants are not growing well. A good quality substrate can be costly but will pay off in the end. All plants need a supply of Iron (Fe) to grow. Aquarium plantation soil such as Tropica provide a long lasting supply of Fe to the plants through the roots. While each of these products can be costly per bag to buy, it provides you the best start to growing nice plants. I personally have used both with great success. Plants "will" grow in your average aquarium gravel but the size of the gravel is very important. It needs to be a finer grain in size and it will also need to be fertilized to provide the nutrients to the plants. I would suggest a layer of peat and Laterite under regular aquarium gravel or sand to provide the Fe needed by the plants. When using this method you must take care not to disturb this layer over time. If it is disturbed and allowed to enter the water column you could create "nuisance algae" problems.

Whatever you decide on for a substrate keep in mind that the depth should be about 3 inches. A common practice to save on the cost is to layer your substrates. By this I mean to set down 2 inches of an Iron enriched substrate (Flourite, Eco-complete, etc.) and then cap it off with either fine gravel or even sand. I use sand in all my tanks through personal choice, in a small way I believe that there is a better nutrient uptake to the plants with sand mixed in due to root contact with the substrate but I cant prove it. Sand mixed in also makes planting of smaller, delicate plants easier. Here is an article on using Sand and Flourite with photos for example.


Here is where the success or the failure of your planted tank can happen. The Aquarium Lighting supplied to you when you first purchase your tank is only intended for viewing your tank , the lighting is very much under powered to successfully grow a majority of plants in.

There is a formula called "Watts Per Gallon" that can get you close to the target amount of watts you will need to grow most plants but needs to be fine tuned for some of the more demanding varieties of plants. Normally 2 1/2 - 3 watts per gallon will grow the majority of plants available that require "Moderate" light. Lets use an example tank... If you take a common sized tank such as a 55 Gallon and only use the "supplied lighting" for that tank, normally 2 - 40 watt Flourescents, and do the math, 80 watts total divided by 55 gallons you will find you are barely over 1 WPG... very little grows in 1 WPG other then Algae.

Nutritional Needs of Plants

Now that you have your tank setup with a good substrate and good lighting you need to supply your plants with a balanced diet of nutrients to begin growing a beautiful planted tank for your fish. First of all, the stronger the lighting you have, the "hungrier" your plants will be. If they lack any specific nutrients you may find yellowing leaves, stunted growth, spindly stems, etc., all of which are signs of a nutrient deficiency. The key is to find a good balance between lighting and nutrients to get the optimal growth from your plants without being overcome with algae. Algae will normally appear when we ignore an important piece of the nutrient plan.

When should I start fertilizing my tank? It is common practice to allow the plants to get established in your tank for about 4 weeks or so before they show a need for fertilizers. This time could be longer in a lower lighted tank or sooner in a higher watt situation. The only way to know when to start is by watching the plants health. Growth rate is normally slow in a new tank but plant health is easily determined.

What do they need?

Micro Nutrients These are available to us through our tap water and commercially sold liquid fertilizers such as Flourish, Kent , Tropica MasterGro , etc. Start off by dosing per the bottle instructions. With time and plant growth you may find the need to up your dosages slightly. Excessive dosing will promote algae growth.

Macro Nutrients (Nitrogen, Phospherous, Potassium)

Nitratessupplied using potassium nitrate (KNO3) Target is 5 - 10 ppm Phosphatessupplied using monopotassium sulfate or Fleet Enema Target is .5 - 1 ppm Potassium supplied using potassium sulfate (K2SO4) or potassium chloride (No-Salt) Target is 20 ppm

Warning - Additional care must be taken when dosing macro nutrients .Over-dosing of macro's at best will only create algae, but at worst will kill your fish. Be sure to have quality test kits on hand and dose the tank in small increments. The process of determining your fertilizing regimen takes weeks to set and it can change again with time.

Substrate Fertilizers

Many plants (Swords,Crypts etc.) feed primarily through their root systems and need to be fed accordingly. There are fertilizers sold on the market in tablet form which get pushed into your substrate at the root base of the plant. Popular brands are Tetra Initial Sticks, Flourish Tabs, Root Tabs Use these per package instruction and always bury them deep in substrate.

What about CO2?

The addition of CO2 is very important to achieve lush growth of your plants, especially when your tank lighting is anywhere above 2 1/2 WPG. In low light tanks where the demand is small for your plants CO2 addition is generally not needed, but as you increase the strength of your lights, you are in turn increasing the demand for more carbon to get the most out of your plants. The target range for CO2 is usually anywhere from 20 - 30 ppm.

159 views0 comments
dog photo thai.jpg
bottom of page