This is the procedure to prepare K solutions for testing the K test kit.

5 test solutions are made – 1, 5, 10, 20, and 30 ppm.

The 5 test solutions are made from two K solutions:

Solution 1, 1,000 ppm: Used to make the 20 and 30 ppm test solutions,

Solution 2, 10 ppm: Used to make the 1, 5, and 10 ppm test solutions,

**Solution 1: Volume 2 liters, K concentration 1,000 ppm:**

Add 3.55 g of K2CO3 in 2 liters of RO

**Solution 2: Volume 100 ml, K concentration 10 ppm:**

Using Soluton 1 to prepare Solution 2.

Desired volume: 100 ml

Desired concentration: 10 ppm

Calculations:

Start ————> End

1,000 mg/L —-> 10 mg/L

Solution 1 ——-> Solution 2

Formula: C1V1 = C2V2

1,000.x = 10.100

x = (10.100):1,000 = 1 ml

=> 1 ml of Solution 1 added to 99 ml RO results in 100 ml of 10 mg/L (Solution 2)

**Prepare the 1, 5, and 10 ppm test solutions from Solution 2:**

For 1 ppm:

10 ml of Solution 2

Add to 90 ml RO

Result: 100 ml of 1 mg/L K solution

For 5 ppm:

50 ml of Solution 2

Add to 50 ml RO

Result: 100 ml of 5 mg/L K solution

For 10 ppm:

Use 100 ml of Solution 2

**Prepare the 20 and 30 ppm test solutions from Solution 1:**

For 20 ppm:

2 ml of Solution 1

Add to 98 ml RO

Result: 100 ml of 20 mg/L K solution

For 30 ppm:

3 ml of Solution 1

Add to 97 ml RO

Result: 100 ml of 30 mg/L K solution

*********************Using a tester to get the K result in ppm**************************************

This is an experiment log using the Hanna HI713 Phosphate tester to measure a sample of water treated with tetraphenylborate to make an opalescent suspension whose density matches the amount of K. That is the principle of the JBL K test kit.

The Hanna P tester’s 525 nm LED light might be used to get a reliable K reading skipping the subjective JBL method based on looking at a black X through the opalescent reacted sample or the baby blue end point of the Salifert method.

K was tested using JBL’s K test kit. Daily tests consistently showed 8-15 ppm K.

At the same time a K test by Salifert showed consistent results of 20 – 25 ppm K.

The JBL reacted sample showing 15 ppm K was placed in the Hanna P tester as if it was a reacted P sample. It showed a result of 2.28.

Log of the readings:

Sample #1 ==> [JBL] = (Hanna Tester)

01 ==> [15] = (2.28)

02 ==> [15+] = (2.47)