Why will pool water not hold chlorine pH and all other levels are great have tried stabilizer which does work either had checked atlocal store to no avail?

Several factors could contribute to pool water not holding chlorine pH, even when other levels are great and you have tried a stabilizer. Here are some possible reasons:

1. High demand for chlorine: Certain elements in the pool water, such as organic matter (e.g., dirt, leaves, body lotions, and sweat), can react with chlorine and cause it to be depleted quickly. Ensure you keep your pool clean by regularly removing debris, vacuuming, and brushing the walls and bottom of the pool.

2. Insufficient stabilizer: The stabilizer, also known as cyanuric acid, helps protect chlorine from being broken down by sunlight. While you mentioned you have tried a stabilizer, it might be helpful to check that it is at the appropriate level for your pool size. Ideally, the stabilizer level should be between 30 and 50 parts per million (ppm).

3. Improper pH balance: Chlorine is most effective when the water's pH is between 7.4 and 7.6. If the pH level is too high or too low, it can affect the efficiency of chlorine. Ensure that you regularly check the pH level and adjust it if necessary.

4. Faulty test kit: If the test kit you are using to measure the chlorine and pH levels is not accurate, it can lead to misleading results. Consider using a different test kit or taking a water sample to a professional pool store for analysis.

5. Other contaminants: Certain other chemicals or contaminants in the pool water can interfere with chlorine's effectiveness. For instance, high levels of metals like copper or iron can react with chlorine and reduce its efficiency. Check for any potential sources of contamination and address them accordingly.

6. Outdated chlorine: If you are using chlorine in the form of tablets or granules, it is possible that the chlorine has lost its potency due to age or improper storage. Ensure you are using fresh chlorine and replace it regularly according to the manufacturer's instructions.

7. Algae or bacterial growth: Algae or bacteria can consume chlorine, reducing its effectiveness. Regularly check for signs of algae growth and treat it promptly. Use a proper sanitizing shock treatment to eliminate bacteria.

8. Bather load: A high bather load can introduce more contaminants and organic matter into the pool water, which can increase the demand for chlorine. Consider limiting the number of bathers in the pool at any given time.

Address each of these factors systematically and make adjustments as needed. Additionally, regular maintenance and proper water care practices are crucial to maintaining a healthy and balanced pool environment. If the problem persists, it might be best to consult with a pool professional for further evaluation and assistance.