For quite some time, I've experimented with different fertilization methods in order to achieve the optimum balance for a planted tank. I've followed the two main methods currently available: the PPS (Perpetual Preservation System) and the EI (Estimative Index) only to realize these methods aren't for everyone, and some folks require a tailored method for their own planted tank. The aforementioned methods can certainly work for many, but they lack consideration for what the aquarist is actually trying to achieve. I've studied some great planted tanks and their owner's approach towards their fertilization regimen, and I've found one thing in common: minimalism and consistency.
Thus I propose a new method; one that is relies upon the tailored needs of each tank and is based on such. This method and article requires the basic knowledge of nutrients necessary for the planted tank, and focuses on how to implement them in a specific tank. Such basic information is readily available, so I will not elaborate upon it. I will make no bones about it: this method will require time, patience, and observatory skills. It will require some testing in order to recognize trends in nutrient use, but for the most part, testing will be minimal. Our focus will not rely upon nutrient levels as a gauge, but primarily the plants and their proper growth.
Table of Contents: Post 1 Introduction Starting Fresh- Starting a New Planted Tank
- Resetting an Existing Tank
- Keeping it Clean
Post 2 Fertilizing to Suit Trace Nutrients- Iron
Macro Nutrients- Nitrogen
Post 3 - Phosphorous
- Potassium
Introduction
You will need to understand a few "basics" in order to get started. This article is geared towards a planted tank that implements the use of carbon dioxide (CO2) injection and moderate to higher lighting, but is certainly not limited to these light conditions. It is not necessary to have very high light, but rather light that intense enough to adequately penetrate to the bottom of the aquarium. This method will compensate for the lighting on each tank. However, I highly recommend the use of a pressurized CO2 system, or at least the adamant control and use of DIY, as you will soon see the extreme importance of a stable source of CO2.
You will also need to know your tap water's parameters such as KH and GH. The pH of your tap water is not all that important, but it is good to be aware of it when acclimating new fish to your tank. KH (carbonate hardness) can play a significant role in the types of plants you wish to grow. For example, certain soft water plants will not grow well in water with a high KH. While most plants can thrive in any water, growing Rotalla macrandra in a KH of 15 degrees will not work. However, the common Amazon sword plant will do very well. The composite GH figure is not very important as a whole. In very high light conditions, you will need to know the levels (and ratio) of Calcium and Magnesium of your water. Ideally, a 2:1 (calcium:magnesium) ratio is ideal, but if it's a little off, that's ok. You can obtain all of this information for free by contacting your local water department and asking for a water report or by viewing it online at their website if they have one available, or simply by speaking to a representative. Why not test it yourself? Because their test kits are better than yours.
Starting Fresh
When beginning this regimin, or any for that matter, it is important that you start out on a clean slate. Muddled up water will lead you astray every time, and you will never be able to draw accurate conclusions. The goal here is to minimize extraneous variables. If you are beginning a new tank, then you will be starting fresh. If you are struggling in your current attempt at growing plants and find algae easy all too easy to grow, then you will find the following steps useful.
Starting a New Planted Tank
1. Have ALL equipment ready to go. This includes the filter(s), heater(s), lighting, substrate, CO2 system, and most importantly, plants--and plenty of them. Don't be scared; plants are your friend. They don't like to be alone and prefer lots and lots of friends (plant heavily!). The use of activated carbon in your filters would be a good idea for a while.
2. Set up equipment. Have it ready to plug in/turn on, substrate layed out, hardscaping set, plants ready to plant. Fill tank enough with water so that you can easily plant. Plant all plants. Fill tank the rest of the way. Turn on all equipment.
3. Allow 2 days to establish proper temperature and CO2 levels. Light duration should not exceed 12 hours (10 is adequate in most cases). After the third day, perform a small water change, 20%, using a hose small enough that you can suck any debris from the substrate (such as Flourite dust). Do not disturb the substrate by poking into it.
4. Three days later, do another small water change. The idea here is to prevent any kind of nutrient from building up. Do not disturb the substrate, filter, and do not bother the activated carbon (if used).
5. Repeat step 4 until you begin seeing new plant growth in the form of new, submersed leaves. You should begin removing old, emersed leaves before they decay. You should also now add algae eating fish/critters such as otocinclus catfish, SAE's, and shrimp. They are not required, but can help.
6. Keep doing the water changes until you notice plant deficiencies (pale leaves, veining, pinholes in leaves not due to fish, etc.). At this time, you should have a trace fertilizer ready. Also, you should have a Potassium (K) fertilizer on hand. We want to keep N & P out of the water until absolutely needed. Read on to find out about fertilizers. You will want to dose every other day, in small amounts. Do NOT fertilize before your plants show deficiencies!
7. It's now time to clean the mechanical media portion of your filter. If using power filters, you will need to keep the water changes up. These filters usually require an entire cartridge to be removed and replaced, thus eliminating much of the needed bacteria. If using a canister, clean the mechanical media and/or filter pad. Do NOT clean any dedicated bio media you may have. Perform the water change (both filter types) after the cleaning of the filter. Canister filters have a nasty habit of spewing out debris when started again. We are in a transitional period. Until the plants can fully sustain themselves without the presence of algae, they need all the help they can get.
Resetting an Existing Tank
1. Remove all plants, prune/remove all algae and infected leaves. Place them in a container with no water. Scrub the tank glass, silicone, equipment until it looks like new. Leave the filters running while you do this. Do NOT disturb the substrate. We want to prevent disturbing any and all bacteria.
2. Allow some time for the filters to pick up mulm and debris, while allowing the rest to settle. When the water is clear again and the debris has settled, use a hose small enough to suck the debris & mulm from the top of the gravel while only allowing for a 20-30% water change. Leave the filter(s) running if possible to capture any extraneous debris.
3. Replant the tank, minimizing the disturbance to the substrate. A mild harrowing of the substrate is ok, just don't go digging. Utilize a UV sterilizer if you have one. Refill the tank. Do not fertilize. Add activated carbon to your filters if possible (optional), but do NOT disturb or clean the bio media. We do NOT want to disturb the bacteria! Your filter flow may be reduced, but that's ok. We'll get to that later.
4. See step 4 above, skip step 5, and eventually continue to step 6 & 7.
Keeping it Clean
After having set a course to a "clean" tank, our goal is to keep it that way. Build-up of any kind is bad. No excess mulm, no excess nutrients, no excess debris, and no dead spots. When a planted tank is kept clean, it's far easier to maintain. It also substantially reduces the amount of wastes which can lead to the fouling of the water and excessive algae growth. While excess nutrients such as nitrogen, phosphorous, and potassium do not actually contribute to algae growth, saturated waters do not help matters. Remember: minimalism and consistency are the keys.
When beginning a planted tank, it's usually a good idea to utilize fast growing plants in order to keep the consumption of nutrients high. This helps stave algae off. In an established tank with slower growing plants, it's important to keep a clean environment so that nutrient build-up does not occur. In most cases, as long as water conditions are stable and plant growth is positive and stable, algae will not be a problem.
But how does one go about choosing the right fertilization method for his/her tank? Let's start by choosing the right fertilizers and following up with the right amounts.