The alkalinity of the pond is very important in maintaining the health and cleanliness of the water. If the alkalinity level is too low, the pH of the water can increase and it is not safe for swimming. Fortunately, homemade baking soda can deal with low levels of pool alkalinity. By mixing the right amount, you can enjoy the pool on hot days!
Step
Part 1 of 3: Testing Alkalinity with the Device
Step 1. Purchase a titration test kit
The titration test kit is a comprehensive measurement system for testing the alkalinity level in a pond. These kits can be purchased at a pool supply store or online.
You can also use an alkalinity test strip, although the accuracy is not very high
Step 2. Take a sample of water from the pond at elbow depth
Dip the tube from the testing device into the water. The water at this depth has not been contaminated with air and sunlight.
You only need 25 ml of pool water to do the test. Drain all excess water from the tube
Step 3. Add 2 drops of sodium thiosulfate
Squeeze the tube gently so it doesn't drip too much. Make sure the mixture is stirred so that the water and chemicals mix evenly.
Step 4. Drop 5 drops of alkalinity indicator and stir the tube
You will see the color of the water change from clear to green. Keep stirring until the color is consistent throughout the jar.
Step 5. Add sulfuric acid reagent 1 drop at a time until the liquid turns red
After each drop, mix in the water. Count the number of drops added to the water. Once the solution turns red, stop adding sulfuric acid.
Wear gloves when handling sulfuric acid in case it spills
Step 6. Multiply the number of drops by 10
The result is parts per million (ppm) of alkalinity in your swimming pool. The alkalinity level of the pond should be within 80-100 ppm. A lower number can affect the pH of the pool while if it is higher, lime scale will appear.
If the alkalinity is higher than 100 ppm, do not add baking soda to the water. Instead, use muriatic acid or sodium bisulfate
Part 2 of 3: Measuring Pool Volume
Step 1. Find the length and width of the pool to calculate its surface area
Use a tape measure to determine the length and width of the pool if you don't already know it. Multiply the length and the width to find the total surface area. The area of the pool is easy to calculate if it is rectangular.
- For circular pools, measure the diameter of the pool and divide by 2 to get the radius. Square the radius and multiply by pi (π).
- For a triangular pool, multiply the length of the side by the height of the triangle (the distance from the base of the triangle to the farthest corner. Divide the result by 2 to get the surface area.
- If you have an irregularly shaped pool, find the average of each measurement. Measure the longest and shortest sides, then add them up. Divide the answer by 2 to find the average length. Repeat the process to find the average width.
Step 2. Average the shallowest and deepest depths in the pond
Measure the height at both ends of the pool using a tape measure. When you've found the shallowest and deepest depths in the pool, add and divide by 2 to get the average depth.
If the pool is all the same depth, you don't need to find the average depth
Step 3. Multiply the surface area and depth of the pool to find its volume
Once all the required variables are known, multiply to find the pool volume. The result is in cubic meters.
Step 4. Multiply the volume by 1,000 to get liters
There are 1,000 liters in 1 cubic meter. Multiply the volume depending on the measurement system to find the amount of water in the pool.
Part 3 of 3: Mixing Baking Soda
Step 1. Add 570 grams of baking soda per 38,000 liters of water
Thus, the alkalinity of the water will increase by as much as 10 ppm. The amount of alkalinity that needs to be adjusted determines the amount of baking soda that needs to be added according to the volume of the pool.
For example, if you change the level from 60 ppm to 80 ppm in a 38,000 liter pond, add 1,100 grams of baking soda
Step 2. Use 910 grams of baking soda per day
Adding too much baking soda to the water at a time can increase the pH of the water. Let the baking soda settle and mix it with the water before adding it back in.
If the alkalinity level needs to be added further, wait until the next day before adding the baking soda
Step 3. Pour the baking soda into the depth of the pool
Pour the baking soda in a circle. Initially the pool water will be cloudy. The baking soda will sink to the bottom of the pool and settle before it begins to mix.
To avoid clouding the water, pour the baking soda directly into the skimmer
Step 4. Retest the water after 10 hours and adjust if necessary
Pool water needs to be pumped and circulated through a full cycle before the water can be tested again. Check the alkalinity level using a testing device.
- Allow the pool to run a full pump cycle, which is usually 10 hours before swimming.
- If the alkalinity is still not ideal after the first baking soda treatment, add it until it reaches the desired ppm.
