Magnesium in Aquaponics

Aquaponics systems are almost always going to be lacking magnesium, causing a hole host of issues. 
When our plants are not getting enough magnesium, you can expect the following to happen. Not always everything, but you could see a combination of multiple issues.

• On old growth, you will see yellowing between the veins of the leaves.

• Older leaves will yellow at the edges leaving a green arrow head shape on the leaves.

• Dead edges on the outside of the leaves may form.

• You may also find brown spots on the leaves.

• The most affected leaves will start to fall off.Arrow Head Shape Green area.

Dead Brown Spots on leaf.

More severe brown spots. The plant will sacrifice this leaf soon.

What else will the lack of magnesium cause?

Lack of flowering can cut the amount of fruit your plants will produce. Adding magnesium at the correct stage can greatly increase the amount of fruit you will get from the plants.

Click here to get your magnesium plant supplement.

There are two common products use for this. 

First is Magnesium Sulfate.  This will only add magnesium.

Next is K-Mag. This product will add both magnesium and potassium, which all aquaponic systems will be lacking as potassium is not found in our water here on planet earth for the most part.

Potassium Deficiency In Aquaponics And Aquaponic Plants

Potassium deficiencies in aquaponics as well as in traditional soil gardens is quite common. In this article we will show and tell you what the deficiency looks like as well as what products to use to correct the issue. You can find the links at the bottom of the article as well as a brief description of how to use each.

The symptoms are as follows:

• Old Growth Affected First
• Plants Will Wilt In The Heat Of The Day
• Slight Marginal Chlorosis At First
• Cupping or Puckering Of Leaves
• Leaf Margins and Dying of The Tips of The Leaves
• Abnormal Fruit Development

 See the pictures below for a visual description of the symptoms.

Through years of growing in aquaponics in our own systems, we have found that for us as well as most others around the world see a potassium deficiency in there plants more often than any other nutrient deficiency. Next is iron deficiency and then magnesium deficiency. 

There are several ways to treat a potassium deficiency, some quicker than others. Below is a list of the products that you can use to correct potassium deficiencies and to keep them at bay for a prolonged period. 

A common misconception is that once you treat your system for any deficiency, it is gone for good. This is just not the case!

We have learned over the years to be proactive to keep our plants healthy and the produce we harvest full of the vitamins and minerals that we need in order to keep us healthy. For plants to do this, the correct minerals must be present in the system water or in the soil, or be sprayed on the plants.

Click on the product listing to view the products.

• TrueNute Potassium Silicate (Most Popular)
• TrueNute Potassium Sulfate
• TrueNute Seaweed Extract

How to use!

TrueNute Potassium Silicate can be sprayed on the plants or added to the system water. It can raise the PH of your system, so you need to be careful not to add it to the system water if your PH is already high. When spraying it on, you will only use 1/2 a gram to a 1 gallon spay can of water, and the same for a soil drench, do this weekly. Use 1/2 of an ounce per 100 gallons of water in your aquaponics or hydroponics system water. Potassium silicate is also used to raise the PH of the system safely while adding potassium and silica both to the system. The benefits of the silica are tremendous. Remember to not raise your PH more than 0.2 per 24 hours so as not to stress your fish.

TrueNute Potassium Sulfate is very simple to use. Only add it to your system water, never spray it on. Add at a rate of 1/2 ounce per 1000 gallons weekly.

TrueNute Seaweed Extract can be used both as a spray or added directly to the system water. To add it to the system water, add at a rate of 1 ounce to 1000 gallons of system water per week. To spray it on, add two tablespoons of extract to one gallon of water, and then use 1/4 cup of the mix to a one gallon spray can, and fill it the rest of the way with water, then spray it weekly.

Iron Deficiency In Aquaponics - Iron In Aquaponics | Deficiencies Testing & Chelated Iron

Do we need to add iron to our Aquaponics System? The answer in 99% of the cases is YES. Iron deficiency in Aquaponics systems is almost guaranteed to occur over time due to the fact that soluble iron does not naturally occur in our water that is added to the system either when we first fill our systems or when we top off the system as needed.

So how do we know if our plants are deficient in iron? As described by most, it starts with a yellowing of the leave between the veins of at the leaves on the new growth of the plant. The veins will remain dark green. As this progresses the leaves will start to turn whitish and begin to die back. The plants growth is stunted, even if you don't realize it, as all your plants in a given system have the same deficiency.

What does this deficiency look like? Here are some pictures that will help.

Cucumber 

Remember, iron deficiency shows up in the new growth, so if you see this in the older growth, you may be seeing a potassium deficiency instead.

Peppers at True Aquaponics

If you also have a potassium deficiency, and you add iron, the iron deficiency will not be corrected as quickly while your plants are still lacking potassium. Properly dosing both will insure your plants not only uptake what they need, but they will also be able to more easily move iron where it needs to be.

Strawberry

We have seen this with most strawberry growers, and have noticed that the berry yield is much lower with smaller fruit. Everyone we have helped to correct this issue has reported much better plant growth and fruit production.

Tomato At True Aquaponics

Iron deficiency is very easy to diagnose in tomato plants and it happens very quickly due to the very fast growth rate of the plants.

Cannabis Plant

Yes, lack of iron will hurt your cannabis crop as well. We have a great deal of clients that grow cannabis where it is legal side by side with their fruiting plants as well as leafy greens and report seeing the deficiency across all the plants at the same time. After the proper iron chelate is added to the system, the plants will recover if the damage is not too severe.

So with all the information on the internet about chelated iron, it is hard to tell which one you should actually use in your system to get the maximum effect while causing the least toxic damage. For Aquaponics there are three types that are available. The first, cheapest and most toxic is FeEDTA. It is used as an herbicide, but worse, it causes some phytotoxic conditions that most are not aware of. I am not going into that science as it is very in depth and hard to follow, however there are iron chelates that are not toxic. FeDTPA and FeEDDHA are both widely used in Aquaponics to bring up the soluble iron content of the system water without the toxins. FeDTPA 11% is the most commonly used, however many folks use this product at the wrong pH level.  The correct level to use this product is from pH 7.5 and below, above this level you need to use FeEDDHA 6%.  This product is soluble from the pH in the low 5's up to a pH in the 9's. Overall it is the best product and the least toxic to your system.  One thing to note about this product is that it will turn your water red. FeDTPA  Will only turn your water slightly brownish or yellowish.  FeDTPA can also be used as a foliar spray, cutting down on the amount of the product that needs to be used.

TrueNute Iron Chelate EDDHA 6%

FeEDDHA needs to be used if your PH level is above 7.5 in order for your plants to be able to uptake the iron.

TrueNute Iron Chelate DTPA 11%

FeDTPA can be used if your system PH is at 7.5 or below. Above 7.5, the availability of the iron drops drastically.

One common misconception is that iron in the form of rust is water-soluble, this is not true. Although rust appears to move around the system more freely it is actually ferric iron and is non-soluble, meaning the plants cannot uptake the iron. In order for plants to able to uptake iron, it has to be ferrous iron. The difference between ferric Fe+3 and Ferrous Fe+2 iron is ferric iron has three positive ions this causes the iron to be non-soluble. Ferrous iron has only two positive ions and therefore can easily be taking up by your plants. What this means is that if you put rusty nails or any other Iron based metal into your Aquaponics system, the iron released into the system will be ferric iron. So with that said, putting re bar, nails or any other steel or iron pieces will only raise the ferric iron content in the system which is no help. Also, there is no way of knowing what other heavy metals will be released into the system water that could be harmful or even deadly to your fish. So it is just not worth the risk.

Here at True Aquaponics, we take a proactive approach to nutrients in our Aquaponics Systems today instead of waiting on the plants to show signs of deficiencies. By waiting you hurt production and open your plants up to attack by pest as well as bacterial and fungal attack. With proper dosing rates, these issues can be avoided and your production will stay at its maximum and the produce will give you a much higher mineral content making it very healthy to eat. We know that there is little or no naturally occurring soluble iron or potassium in water from the tap or water well unless it has been added for some reason. This is not likely to be the case. So for these nutrient supplements and others, we have to add them to our aquaponics system water or spray them on our plants in order for the plants to be healthy and for us to be able to harvest food that is in turn healthy for us to consume.

After all, if you want unhealthy food to eat, head to the supermarket, they have lots of that.

Here is a link to find the Iron Chelate you need for your Aquaponic or Hydroponic system. 

Below you can find the two Iron Chelates hat we use.

• TrueNute Iron Chelate DTPA 11%
• TrueNute Iron Chelate EDDHA 6%

Want to see all the products we use and recommend? Click the next link.

All Our Products

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