Flushing Coco 101

This method is used to check the ec and ph values of a medium and useful when flushing. It is recommended by Canna and supported by Geary Coogler, B. Sci. Horticulture, HORTISOL North American Research...Enjoy

The 1:1.5 Extraction Method

A reliable method for measuring the nutrient levels in coco coir is using the 1: 1.5 extraction method. EC and pH of the root environment can be determined by using this method. The pH and EC of the drain water generally deviates from the actual root situation, as coco coir is able to retain and release elements.

1) Take a sample of coco. This can be done with a soil core sampler or a trowel. To get a representative sample the coco must be collected from as many places as possible.

2) Collect the sample in a bowl and determine whether it contains the right amount of moisture. The coco has the right amount of moisture if moisture disappears between your fingers when you squeeze it. Add de-mineralized water if necessary and mix the coco.

3) Take a ½ pint (250 ml) measuring jug and fill it with just over 4 fluid ounces (150 ml) of de-mineralized water. Add coco to the ½ pint (250 ml) mark.

4) Fully mix and allow the slurry to settle for at least two hours.

5) Mix again and measure the pH.

6) Filter this material out and measure the EC of the water remaining.

For checking the ec of nutrient solution:
The target values for EC are between 1.1 and 1.3 (of course, lower is acceptable too!).
Target values for pH are between 5.3 and 6.2.

For checking the ec for flushing:
The ec of water going in should match the ec going out or,very close