How to add Calcium Chloride to a swimming pool
SAFETY NOTES:
- Pre-dissolve all dry chemicals in a bucket of water before adding them to the pool.
- Always add chemicals to water; never water into chemicals.
- Never throw dry chemicals directly into the pool.
- Never allow undissolved chemicals or salt to sit directly on a pool surface.
- Calcium Chloride gets hot when dissolving. Use caution and safety gloves/glasses.
Overview
Calcium hardness can increase in a few ways: 1) calcium chloride, 2) Cal Hypo chlorine, and 3) the water steals calcium for itself.
If calcium increases but was not manually added by the pool owner or operator, you know it came from the surface or tile grout. In the case of vinyl liner or fiberglass pools, low-LSI water can cause deterioration of the surface. Calcium hardness is often under-appreciated and is essential, especially in cold water.
This procedure outlines how to add calcium chloride to water. We strongly recommend pre-dissolving and chelating calcium chloride prior to adding it into the pool.
Related Article: How to add Calcium Chloride to a swimming pool
You will need:
- Test kit
- Liquid and Dry measuring cups
- Protective gear (glasses, rubber gloves)
- The Orenda Calculator App
- At least one clean bucket (or the Orenda Startup Barrel™)
- If using the Startup Barrel, you will need a hose to fill the barrel, and
- Channel locks large enough to unscrew the 2" drain plug at the bottom of the barrel
- Calcium Chloride (Flake or Prill/Granular)
- Muriatic Acid
- Orenda SC-1000
- Stirring stick
Procedure
- Bring your test kit, measuring cups, and chemicals to the pool, and collect a half-full bucket of pool water.
- Test the water for pH and calcium hardness (at a minimum). We recommend also testing for total alkalinity and water temperature.
- Once water chemistry is known, use the Orenda App to figure out the calcium chloride dose needed.
- Do not exceed 5 pounds of calcium chloride in a single bucket. Instead, divide up the dose and repeat the process using multiple buckets of water until you distribute the entire dose.
- Alternatively, if you're using the Orenda Startup Barrel™, you can safely add a lot more calcium chloride at a time. The 55-gallon barrel can dissolve 150 pounds at a time, and the 30-gallon barrel can handle 100 pounds at a time.
- If you're using the Startup Barrel™, consider putting a 1.5" ball valve on the bottom for easier use. This allows you to empty the barrel into the pool much faster with less risk of spilling on the deck. See the photo below.
- If you're using the Startup Barrel™, consider putting a 1.5" ball valve on the bottom for easier use. This allows you to empty the barrel into the pool much faster with less risk of spilling on the deck. See the photo below.
- Add the calcium chloride to the bucket of water and stir.
- Add one ounce of SC-1000 per 5 pounds of calcium chloride to chelate the calcium and help it dissolve. This pre-chelates the calcium before it goes into the water, ensuring it will stay in solution.
- Add one ounce of muriatic acid (if the water's pH is 7.8 or higher).
- Once the bucket completely dissolves and begins to clear, pour it around the perimeter of the pool.
- Repeat the process as necessary for more significant amounts of calcium chloride.
Additional Information
If your pool requires an acid treatment to reduce pH or alkalinity, acid can be pre-diluted in the same bucket as calcium chloride. Never add acid to calcium directly, but it is okay to add acid to the bucket of water that is also dissolving calcium chloride. Always use safety gear, and remember that calcium chloride gets hot when dissolving. Use caution when handling.
Related Procedure: How to Implement the Orenda Program