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Nutrient Mixing Guide
Nutrient Mixing Guide

A general guide to mixing nutrients and changing the water tank.

Andrew Hobbs avatar
Written by Andrew Hobbs
Updated over a week ago

Your plant requires a weekly feeding with nutrients. The nutrients are pre-measured and packaged according to each week of the grow cycle. We also recommend a weekly water change for best results. 

This guide will show you how to mix the water and nutrients and add them to your Mary unit. 

What tools/items do you need?

  1. Bucket - we recommend the orange 19L bucket from home depot. It costs only $4 and can hold the full 13L of water. Pro tip: measure 22.75cm or 9” up from the bottom of the bucket and make a mark - that will be your 13L fill line.

  2. Mixing spoon to stir. 

  3. 1L measuring cup

  4. We highly recommend a pH kit to make sure your water & nutrient solution is within the idea range. 

How do you do it?

Fill your bucket with 13L of water. Open the nutrient pack with the corresponding week # (consult the Mary app if you are unsure of which week to use), pour it into the water and stir vigorously for a few minutes, until dissolved. 

If you are having difficulty in getting the powder to dissolve, you can try a different approach. Fill the bucket with only 12L of water and fill a separate container with 1L of warm water. Add the nutrients to the warm water and stir until dissolved. After the powder has dissolved into the warm water you can then add it to your 12L of water in your mixing bucket and mix thoroughly.

Optional: you can test the EC value of your nutrient solution at this point. 

Once mixed, we recommend that you check the pH balance of your nutrient solution. The ideal range is 5.5 - 6.5 for your plant. In most cases, you will have to add pH down to lower the pH of the solution. We recommend lowering to 5.5-6 since it is normal for the pH balance to raise slightly after being added to the Mary. 

Now that your water & nutrient solution is ready, use the Mary pump to remove the water that is currently in the tank and add the new solution. Keep in mind that 13 L is more than 100% full - we recommend mixing at this volume as it makes it easier to add to the water tank. 

Any tips, tricks, or other things to be aware of? 

Keep in mind that water colder than 17 C may shock your plant. Tap water is usually a little warmer, and you can also let your water sit for a little while to warm up to room temperature. Water that is warmer than room temperature is not recommended as it can encourage root rot. 

It is a good idea to read our pH balance guide ahead of time.

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