Miracle Grow for Hydroponics – Good Bad and Ugly

Miracle Gro for Soil
Do Not Use In Hydroponic System

There are many different types of nutrients you can use for your hydroponic system. Miracle grow for hydroponics is one of them and is especially formulated for use in any hydroponic systems, this goes under the brand name of ‘Miracle Gro – AeroGarden – Liquid Plant Food.’  Though it was formulated mainly for an AeroGarden system.


‘Miracle Gro’ has two types of liquid plant food one type for soil and the other for hydroponics. Many people have been using the soil type Miracle Gro both liquid and powder formulas for their hydroponic systems with so-called good results. however, if you search the internet you will find that Miracle Gro plant food for soil is missing some of the important micro nutrients that the soil provides which is essential for healthy plant growth in a hydroponic system.

  The Good

Miracle Grow for Hydroponics
For use in hydroponic system

AeroGarden trade mark is a hydroponic system that is self contained and is purchased as a complete system including grow lights. It consists of small grow pots that are sprayed (from inside the tank) with a water/nutrient mix on a constant on/off cycle.

This provides the plant roots with the required amount of nutrients when sprayed in the ‘on’ cycle and air mix when in the ‘off’ cycle for good growth.



  The Bad

I recently purchase Miracle grow for hydroponics to try it out in my home-made hydroponic system.  The unfortunate thing is there are no instructions on the container other than how to apply it to a AeroGarden System. This is what you will find on the container.

Directions for use: Shake bottle well before using. Add required nutrients when planting seed kits, then repeat every two weeks when the ‘Add nutrients’ alert activates. See measuring cap for required ml measurements.

Instructions: For AeroGarden and other Hydroponic systems.

3 pod Gardens – 4 ml at start-up, and every 2 weeks

6/7 pod Gardens – 8 ml, at start-up, and every 2 weeks

Big and tall plants over 12” in height – 8 ml for first two feedings, 12 ml per feeding thereafter (every 2 weeks)

  The Ugly

The problem is that this does not help if your hydroponic system is not an AeroGarden system.

I sent them an email asking how much nutrient to add for 8 gallons of water. The instructions I received was about 8ml per 1.1 gallons, that is what they use in there system. So after doing the math that would mean for my 8 gallons or 30 litre of water I rounded it out to be about 60 ml  or about 2 ml per litre for the 30 litres.

I used 30 ml of the nutrients, half the recommended dose, and within 24 hours my plants (cucumbers) started to wilt and die. I had to replace the water and just give them a plain water bath to get them to survive. They survived but where not healthy as the roots had started to rot so that was the end of them. Fortunately I had other cucumber plants to replace them for further testing.


The conclusion I think is that with an AeroGarden the roots are not in the water all the time, giving the roots chance to breath.

From further testing over several days I found that 10 ml of the Miracle Grow for Hydroponics to the 30 litre (8 Gallons) of water was the right concentration.

If you have used AeroGarden Miracle Gro please leave a comment below so we can all gain from the experience.

John C




  1. // Reply

    Hi John,

    Great article – I am thinking of doing the same type of system, and wanted to see if you had learned anything since this post? Is 10mL for 8 gallons still the best ratio? And would you recommend the same amount for young plants as well as older larger plants? Thanks in advance for your help!

    1. // Reply

      Hi Ryan,
      Thanks for your question. It one of those situations where less is better than more.
      Quite often you can shock the plants by giving them to much to start as I found out.
      Its best to work up to the recommended mixture of water to plant food ratio.

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