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The School of Aquaponics


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Written by The School of Aquaponics

We are here to push the movement of aquaponics in a forward direction. Our primary focus is help you in your adventure with aquaponics by providing you with the highest level of information. Aquaponics is still in its infancy and we predict that it will be the go to method of farming by many families and urban farmers. Our job is to ensure that they are taught correctly.

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  1. is there any micro nutrients additives that are harmful to the fish in an aquaponics system, that would cause me to need a decoupled system? My wife suffers from MS and the plants mean the most to her for her health and the fish mean more to me, because I love fish. Trying to find a balance.

  2. Just for anyone looking for this it is often called SEQUESTERED IRON at least in the UK anyway. Also, in the UK "chelated" is pronounced "key-lated". Thanks for all the videos!

  3. Thank you! I love your channel and your energy and delivery are awesome.
    But most importantly, you don’t skip the finer details and really take the time to attack the science of how each facet of each component comes together for aquaponics.
    Your video on adding/measuring iron ppm is great and saved me from being a biscuit-headed grower.

    I’m requesting that you do a video detailing the differences between the commonly used types of chelated iron supplements. You use DPTA and I use EDDHA. My water is colored red because of a dye additive in the EDDHA supplement, and I’ve heard that virtually nobody uses a dye additive in the other forms (EDTA/DPTA).

    Can you please do an overview analysis of the commonly used chelated iron supplements? Be it powdered or liquid form.

  4. What’s your opinion on supplementing some or all fish feed with crickets, worms, duckweed, or any other veggies and bugs. If you have any other ideas plug them in. Thanks for getting into all the advanced topics of aquaponics.

  5. Good info, I'm not doing aquaponics but it's not out of the question in the future, and this is wonderful info for pond growth. Just wanted to say thanks, and you have a new sub for teaching good info! 🙂

  6. Dear Brooklyn thanks for this amazing video, Can you please assist me we with advice on how to create the best optimal temperature environment for the aquaponic system?. What do you use to keep the water at a constant temperature for the system. And where do apply the devices in your aquaponic system? Do you instal heating pads inside the fish tank or outside or do you use a different method to approach this matter?

  7. Fantastic video here is some added info I dug up in case some one had other questions.

    Iron in water has many effects on aquatic life, both good and bad. Iron (Fe) occurs naturally in water at a rate of roughly 1-3 parts per billion (ppb) in ocean water, about 1 part per million (ppm) in river water and 100ppm in groundwater. Iron comes from various minerals in the soil, which is why groundwater contains the highest iron concentrations. Iron levels in water vary depending on several factors and can affect aquatic populations, behavior and health.

    Iron Levels in Water
    When unusually high amounts of iron exist in water, this is usually due to pollution related to construction or iron mining. Iron comes in several forms in water. It can be dissolved in the water or so heavy that it forms a precipitate or microscopic solid pieces suspended in the water. Scientists are experimenting with iron fertilization to reduce global warming by intentionally increasing the iron levels in seawater.

    Iron is vital to the life of all aquatic creatures, especially mollusks and green plants. Iron promotes enzyme growth and gives blood its red color. Iron binds to oxygen and travels with it in the blood, transporting the carbon dioxide out. Green plants use iron for nitrogen binding. Phytoplankton, some of the smallest ocean creatures, depend so heavily on iron that the amount of iron present in water limits the amount of phytoplankton that can survive.

    At normal levels, iron is not deadly to any aquatic animals, but at higher levels when iron does not dissolve in water, fish and other creatures cannot process all the iron they take in from water or their food. The iron can build up in animals' internal organs, eventually killing them. Higher levels of iron in fish and aquatic plants also has negative effects on the people or creatures consuming them.

    Large amounts of iron promote growth of algae, which can block sunlight from other plants and can disrupt habitats and feeding practices. Extensive algae presence lowers water freshness and promotes stagnation. Iron fertilization or contamination affects the reproduction and feeding habits of fish and other animals. High concentrations of iron sometimes result in increased acidity of water—killing or hurting aquatic life.
    In animals, the most common iron-containing substance is heme complexes. We’re most familiar with hemoglobin. In hemoglobin, iron helps bind oxygen for transport throughout the body.
    In plants, iron serves many functions but is an essential component in the production of chlorophyll, the site of photosynthesis.
    Without enough iron, plants cannot produce enough chlorophyll, leading to retarded plant growth characterized by interveinal chlorosis. Iron is also a key component of cytochrome—a heme-protein that plays a key role in ATP generation—the currency of cellular metabolism.
    In this capacity, it is irreplaceable to both plants and animals. Iron also plays a major role in many other proteins and reactions.

    Forms of chelated iron
    The most common forms of chelated iron are:

    FeEDTA: This is a slightly toxic form that aquaponics practitioners should not use. This type of chelated iron is commonly used as an herbicide to kill broad-leaf weeds. It should not be used just because of its toxicity, but also because it typically only effectively chelates iron up to the pH range of 6.3 or 6.4. Above this range, it is not a stable chelate. So, using FeEDTA in your consistently pH 7.0 system represents a significant amount of money wasted in comparison to other forms of chelated iron. For this reason, I recommend that AP practitioners do not use FeEDTA. It is ironic that this is the most commonly sold and used form of chelated iron in aquaponics systems as it is fairly ineffective—the equivalent of modern “aquaponics snake oil.”

    FeDTPA: This is what is recommend for most systems at pH values between 6 and 7.5. It is commonly available at lawn and garden stores.

    FeEDDHA: This is what I recommend for systems which have pH values up to 9.0 (let’s hope your pH never gets that high!), and the best all-around form of iron chelate, especially for starting systems. Effective at a broad pH range, FeEDDHA maintains iron solubility in almost all of the water conditions encountered by startup aquaponics systems

    Common thinking about adding chelated iron
    There are two schools of thought on chelated iron addition. But we added a 3rd for this class of growers.

    1) Addition in response to deficiency
    Some say that chelated iron should be applied anytime you see a deficiency. This is a reasonable and reactionary dosing method but ultimately means that your plants must first suffer from iron depletion and deficiency before the problem is addressed. In this scenario plant production can be negatively impacted.

    2) Addition on a regular basis
    The other (and better) school of thought is to apply iron at the standard UVI system rate of 2mg/L every three weeks. (Dr. Rakocy at the University of the Virgin Islands was the first to design a standard DWC aquaponics system. Many of our aquaponics numbers and ratios today are drawn from his research.)
    Iron can also be applied through a foliar application—using either chelated iron or ferrous sulfate mixed at low concentrations. Foliar application is great for fast response. But because iron isn’t a mobile nutrient inside plant tissues, iron will have to be supplemented regularly using this method—a time consuming, and ultimately less effective iron supplementation method.
    In summary, iron can be regularly dosed so that iron deficiencies do not arise in your system.

    3) Is for High Class Growers
    Know what your levels are of Iron. Apply the formula From the School of Aquaponics once every 3 weeks to a month on a regular schedule and set the level of Iron where you want it between 2-3ppm. No need to make things more complex than it needs to be.

    Cost of Chelated Iron
    While many practitioners complain about the cost, when bought in the 5–10-pound bag, chelated iron is really not very expensive, and often even in large commercial systems, will last for many months.
    At the dosing rate above, a 10 pound, $15 bag of chelated FeDTPA will last well over a year or less than $1 per month. At higher iron concentrations it will last much longer.


    Iron makes up about 5 percent of the earth's crust. In industry, it is used as a construction material and to create pigments. In humans, it is an essential element required for hemoglobin to transport oxygen from our lungs to our cells.

    Iron in Drinking Water

    Rainfall seeping through soil causes iron to dissolve and leach into groundwater, including wells and aquifers used to supply drinking water. Iron concentration in wells and aquifers is typically between 0.5 and 10 milligrams per liter, and, as a result of water treatment, iron concentration in drinking water is typically less than 0.3 milligrams per liter. Iron concentrations of higher than 0.3 milligrams per liter in drinking water are noticeable to humans.

    Health Effects

    For humans, the average lethal dose of iron is quite high — between 200 and 250 milligrams per kilogram of body weight, or about 14 grams of iron for a typical 70kg adult. Death results from extensive gastrointestinal hemorrhage. However, iron toxicity is rare, and iron intake from drinking water is typically much too low to raise health concerns — about 0.6 milligrams per day if you're consuming a typical 2 liters of water per day, compared to an average iron intake of 10 to 14 milligrams per day from food.

  8. Your slides use GRAMS until the very last multiplication by 852 liters, when they switch to MILLIGRAMS. Your verbal instructions are consistently in milligrams.

  9. Your school of Aquaponics online academy rocks. Folks asking for lists of what you use…folks need to follow them links and get into your Aquaponics Paradise course. It's very well designed….of course. Wouldn't expect anything less from a Marine. Great work, Sir. Shalom

  10. Thanks Brooklyn for all the great info. Curious about when adding the iron to the system how does that react to the fish. I know it's not harmful but does this alter their growth at all especially in low stock density situations

  11. Dear Best of the Best

    I have an addition here The Fe DTPA works tell Ph 7-7.5 not above that and it is more expensive.
    It is better to add Fe EDDHA which works tell Ph 9 it has around 6-7 % Fe

  12. Thank you sir, One Question/Request :- could you please make an overview video of all supplements you using in you system and please show us the brands also where to buy them?

  13. Pardon my ignorance; is iron not good for for trout &/or talipia? I can't remember where I saw it, but I think I remember reading that both are sensitive to it. And what about invertebrates; (like crayfish), they're supposed to be highly sensitive to iron, no?

  14. Thank you very much, Perfect timing 2 months ago i set up a 300g stocktank indoors i have the hanna tester and 11% iron but i was bein hesitate to do anything because i didn't know what up completely. That equation is gold thanks again!


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