Planted Tank EI Dosing for Dummies

Before you jump into dosing, check out our comprehensive touchdown of Planted Tank EI Dosing

The Estimative Index (EI) is a method that provides simplified directions for delivering additional nutrients to a planted aquarium. The basic premise behind EI is the straightforward introduction of a non-limited supply of nutrients inside of a planted tank over the course of a week. This nonrestricted concentration of nutrients fills the water column and is absorbed by the plants. This method is estimative, so specific measurements of nutrients is unnecessary, and there are no test kits required. EI thereby creates a surplus of nutrients that help the plants avoid deficiencies and thereby encouraging their growth unhindered.


Simply put, you supply only a minimum amount of excess nutrients in order to prevent any deficiencies in immediate availability, but then also follow up with a 25% to 50% water change towards the end of each week in order to prevent any nutrients from accumulating too much. By doing this, you will allow the nutrients to maintain themselves within a certain range and thereby eliminating the need for test kits. Aquarius use the same method with certain fish that they intend to feed heavily so that their growth rate and reading rate increases.

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Fertilizers for Your Planted Aquarium
The primary fertilizers are these macronutrients:

– Nitrogen (N)

– Phosphorous (P)

– Potassium (K)


As well as and these micronutrients:

– trace elements (Plantex CSM+B, Flourish, Tropica Master Grow-TMG).

– Iron (Fe) (which can be supplemented if needed)


These EI target ranges are the levels that you should strive for:

– K+ range 10-30 ppm

– PO4 range 1.0-2.0 ppm

– Fe 0.2-0.5ppm or higher

– GH range 1-2 degrees "extra" 17-40 ppm or higher

– CO2 range 25-35 ppm

– NO3 range 10-30 ppm

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Algae Hiding in Your Planted Tank
In the case that algae forms, those issues are mostly the result of deficiencies concerning the plants as opposed to excessive levels of nutrients, with Ammonium being the only potential exception. In many cases, issues that may attribute to the growth of algae may be the presence of excess light or the essence or insufficiency in CO2 dosage.

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Your Planted Aquarium’s Lighting
The Estimative Index method works best when medium to high light intensities are used with a plan to take. But that does not mean that the method is restricted to setups with higher lighting because you could decrease the quantity of the fertilizers used in order to accommodate a tank that uses a low light setup. In that case, you can also reduce the frequency of dosage to one or two times a week for a tank up to 2 w/gallon.


High light is subject to the type of light that is being used in the size of the take overall. If the lights are positioned about 2 to 4 inches above the surface of the water, high light will be rated above 2.5 watts per gallon for a tank that is 20-100 gallons, if the lights that are being used are of high quality and are operated with reflectors, similar to the quality supplied by AH Supply. But even under that rule, some logic takes will require fewer nutrients while other things that are smaller would require more. Even though this may seem like a mixed-up way of measuring dances the of the lights, it does suffice the method.

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CO2 in Your Planted Tank
30 ppm of CO2 levels at least, is optimal and necessary in order for the plants in the aquariums to strive. If algae growth becomes a complication, immediately remove any visible trace of the algae and the leaves that were effective. After removal, check the CO2 levels again, and it might be a possibility that you need to adjust or reduce the lighting in order for the take to recover.


There is no method of dosing that can compensate for insufficient lighting or an adequate CO2 usage. So it is important that you establish a routine because the habit in which you are regularly dosing, regardless of whether you choose to add a liquid solution on a daily basis, or dosed with dry powders three times a week, the objective is to be consistent when you are dosing and to monitor the CO2 levels very closely.


CO2 demand will decrease with secondary limitation, which leaves hobbyists to make the assumption that the cause of their problems is the nutrients when all along, the CO2 was the real problem. And it will not be until that is addressed that their concerns with algae or lack of plant growth will be remedied. That means it's very important that you make it a priority to keep a watchful eye on CO2 levels when concerning algae or plant growth, as it is a vital component that can fuel growth rates up to 20 times faster when they are correctly implemented. Ample water flow will also assist with the growth, with plants slowing down the rate of flow by as much as 90%.



The Process for Your Planted Tank
The process of which this is done is simple. Each day (or 2-3x a week, weekly for low light tanks) fertilizers are dosed, and the nutrients are absorbed by the plants. With this method using SMS as opposed to precise measurements, we can use general guidelines when dosing fertilizers depending on the specific set up. Every seven days, you need to change the percent of the water in order to reset the concentration of nutrients within the ecosystem. At that time, the dosing regimen starts from the beginning and repeats itself. 50% is simply a guideline, so hobbyists can choose to do less or more depending on what works for them.


Dosing with dry powdered fertilizers works fine, or you can create a stock solution that you use for daily dosage or two to three times a week edition. The choice is up to you, if you are the type of person who beat your fish every day, then liquid dosing works sufficiently well. No rule exists that dictates that teaspoons must be used, but new people to the hobby find that it is easier to manage until they gain comfortability with this approach. Even though a 50% weekly to water change were informed that the maximum possible accumulation remains under two times a number of nutrients dosed for the week, you can prevent even less buildup of nutrients from accumulating by performing a water change that is larger than 50% on a weekly basis.


So if you added 10 ppm of NO3 dosage, the more you would have to worry about concentrations reaching 20 ppm if you were performing a 50% weekly water change, and no uptake happened in the process. So, obviously the more there would with a 90% water change on a weekly basis would be approximately 12 ppm. Course, there's more work and effort involved in order to perform a 90% water change versus of the percent change, but you will benefit from the smaller ranges. You will change the most effective way to alter the emulation and prevent buildup.




General Dosing Guideline For High Light And Well Planted Aquariums

10- 20 Gallon Aquariums

+/- 1/8 tsp KNO3 (N) 3x a week

+/- 1/32 tsp KH2PO4 (P) 3x a week

+/- 1/4 tsp GH booster once a week(water change only)

+/- 1/32 tsp (2ml) Trace Elements 3x a week

50% weekly water change



20-40 Gallon Aquariums

+/- ¼ tsp KN03 3x a week

+/- 1/16 Tsp KH2P04 3x a week

+/- 1/2 tsp GH booster once a week(water change only)

+/- 1/16 tsp (5ml) Trace Elements 3x a week

50% weekly water change



40-60 Gallon Aquariums

+/- 1/2 tsp KN03 3x a week

+/- 1/8 Tsp KH2P04 3x a week

+/- 3/4 tsp GH booster once a week(water change only)

+/- 1/8 (10ml) Trace Elements 3x a week

50% weekly water change



60 – 80 Gallon Aquariums

+/- 3/4 tsp KN03 3x a week

+/- 3/16 Tsp KH2P04 3x a week

+/- 1 tsp once a week (water change only)

+/- ¼ tsp (15ml) Trace 3x a week

50% weekly water change



100 - 125 Gallon Aquarium

+/- 1 1/2 tsp KN03 3x a week

+/- ½ tsp KH2P04 3x a week

+/- 1.25 tsp once a week(water change only)

+/- ½ tsp (30ml) Trace 3x a week

50% weekly water change



Dosing Your Planted Tank
Direct dry dosing is a perfectly fine practice with this method. Many times, the dose is admitted straight into the water, or dissolved into the water before added to the planted tank. Often times, plan text CSM+B is diluted into a solution to allow for liquid dosing. The solution is refrigerated when stored in order to prevent mold from developing inside the container. HCl acid can also be added to the solution to prevent the multiple relations. Many hobbyists choose to create their own liquid stock solutions and provide the total weekly dosage on a daily basis spread over seven days which allows for narrower control. For those who have a high concentration of fish in the tank. They tend to add less N and P, but because the method is very flexible, it just takes a bit of common sense and child error to figure out what works best.


By sticking with an adequate dosing regimen, your plans will flourish, and you be more than delighted. I was to become acclimated and experienced with the planted aquarium; you will find that you may need to modify your routine for more or less dosage, or even reduce or increase some parts of the routine. Most complications arise from CO2 concentration and the sufficiency or lack thereof of water flow in the case that the nutrients are unrestricted due to the gas and nutrient exchange that occurs within the aquatic ecosystem.


On a final note, limiting PO4 or NO3 will result in a decreased demand for CO2 supply. But those who do not measure or research the ecosystem quickly often conclude that decreasing NO3 levels is what results in the improvement of algae conditions. Mistakenly enough, that line of thinking proves to be untrue when considering that it does not explain tanks that have the same original NO3 concentration do not experience any algae issues.

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