There is one thing that all living things have in common. They all require nutrients to maintain health, growth and system stability. Further to that, all living things require the same basic sets of Macro and Micro nutrients. Plants are obviously no exception. Planted aquariums almost doubly so because by their design they are largely closed systems with little interaction with the larger world except through gaseous exchange, light and temperature, and even those interactions are controlled.
Although our systems are designed to be imitations of natural environments, they are far from natural in that they require our interference to thrive and achieve optimal health. We donâ€™t hesitate to encourage beneficial bacteria and filtration, or temperature control. We test and consider water parameter ranges for their suitability for our livestock and plants. We do all these things and more to encourage a healthy stable system and yet many still often overlook one of the most important building blocks to a healthy planted tank; Nutrients.
What are the different types of Nutrients?
The nutrients necessary for healthy plant growth can be broken down into THREE main categories;
- There are three non-mineral nutrients which are of the utmost importance and are the most readily available in aquatic systems; Hydrogen (H), Oxygen (O) and Carbon (C). Without these, no life is possible. Approximately 95% of all plant dry mass is made of these which are largely drawn directly from the water column.
- Macronutrients are called as such because they are needed in the largest amounts. These are nearly as important as non-mineral nutrients in that without availability in one form or another, plants would not be able to perform the most basic processes required for their survival and growth.
- These are often broken down into two main sets, Primary Macros and Secondary Macros, as they relate to the amounts required of each. Often erroneously, secondary macros are sometimes included in lists of micronutrients but this belies the amounts needed for proper plant health and really should be considered with the macro level nutrients.
- Primary Macros are Nitrogen (N), Phosphorous (P), and Potassium (K)
- Secondary are Calcium (Ca), Magnesium (Mg) and Sulfur (S)
- These are all essential in protein synthesis, chlorophyll production, and leaf and root development. Basically the driving force in plant development and growth after the non-mineral nutrients.
- Although used in much smaller or trace amounts, Micro nutrients can be considered the supporting nutrients to the macros and non-minerals; allowing them to be processed properly and efficiently. They provide support in the processes of regulation and transportation of nutrients, plant metabolization, and cellular stability.
- Micro Nutrients are Boron (B), Copper (Cu), Chloride (Cl), Iron (Fe), Manganese (Mn), Molybdenum (Mo) and Zinc (Zn).
Why do we need to dose?
As noted, although our aquariums are an attempt to emulate nature, they suffer from a few shortcomings that a true natural system does not. In nature, minerals are provided constantly through the water system as it erodes soil and rock etc. and also through plant decay and animal waste. However in a closed system like an aquarium, plant decay can become excessive and create too many uncontrolled nutrients and by products which can stimulate opportunistic algae. As well, fish waste in an aquarium only provides Nitrogen and Phosphorous and then in limited quantities unless the bio-load is significant. None of the other necessary nutrients are provided through either of these sources.
A nutrient rich substrate, such as aquasoil, is a good method to provide the necessary nutrients however these nutrient stores deplete after a number of months and once again, dosing is required to provide the plants the complete set of nutrients they require. This is of course also only a solution to the needs of stem and other rooted plants, and although substrates can leech some nutrients into the water column it is, again, not in amounts necessary to fully support non-rooted plant life.
As well, nutrients in the water supply are not always a reliable source from region to region. At times, well water can be rich in most necessary nutrients but often in sub-optimal ratios. Municipal tap water is rarely rich in the necessary nutrients and is often quite lacking, and this is without consideration for some people supplementing their harder water with nutrient depleted reverse osmosis water.
How should we dose?
In order to provide lush, healthy growth, plants need adequate access to all macro and micro nutrients in complete and sufficient amounts. Any limitation of any single or combination of fertilizers will create deficiencies and limit optimal health. All in one liquid fertilizers or dry fertilizer packages are designed to provide the correct, necessary ratios to virtually all varieties of plants. By providing sufficient amounts of all nutrients, one does not need to chase deficiencies or try to diagnose any single issue. These diagnoses can be problematic because, as noted above, different micro nutrients support and facilitate the proper use of other micro and macro nutrients. Rather than struggling against issues, it is far more optimal to provide sufficient amounts of all fertilizers, ensuring no limitation of availability for plants.
Unfortunately, most commercially available fertilizer solutions offer very lean and lacking options. Most of the major brand names, typically available at local fish stores or big box stores, have multiple bottle treatments with quite poor ratios and often lack some essential nutrients. Many of the more popular brands offer watered down micro elements only or leaner NPK only macro combinations forgetting about the secondary macro nutrients all together.
It is for this reason that an all in one solution like Thrive is preferable to all other liquid fertilizers currently available. Not only does it provide the complete set of nutrients necessary for healthy and sustainable growth but it also does so in ratios which ensures that even the most high demand plants needs are met. Dry fertilizers are also a good option for ensuring proper concentrations and allows for the ability to customize dosing regimens for the user, a method that should only be attempted once one has learned to recognize the needs of their plants through visual cues. Until such a skill set is developed, a liquid all in one may be the better approach.
When dosing complete nutrient sets it is important to maintain regular weekly water changes in order to reset nutrient values, as different plants use different amounts of individual nutrients at different rates. And so to avoid a nutrient imbalance, weekly water changes allow one to be secure in the knowledge that plants are receiving optimal availability to all nutrients.
If you have any questions regarding this article, or any questions in general please do not hesitate to contact me at Colin@NilocG.com. This article was written by Kevin Grant.
Colin / NilocG