The short answer is “every day.”  There is literally something that can or should be done with pool maintenance every day.  That is a little impractical for most people.  For the majority of people, the frequency with which a pool maintenance professional, commonly referred to as a "pool guy," should come depends on various factors, including the size of the pool, the local climate, and how often the pool is used. Here are some general guidelines:

1. Weekly Visits: For most people and in most cases, especially during the swimming season, it's common for a pool professional to visit once a week. During these visits, they can perform tasks such as skimming the surface, cleaning out debris from skimmer baskets, vacuuming the pool, and checking and adjusting chemical levels.
2. Bi-Weekly or Monthly Visits: For pools that are not used frequently or during the off-season, bi-weekly or monthly visits may be sufficient. During these visits, the pool guy can still perform essential tasks to keep the water clean and balanced.
3. Seasonal Adjustments: In some regions, pool maintenance schedules may be adjusted based on the seasons. For example, during the winter months when the pool is not in use, less frequent maintenance may be required.
4. Demand-based: If your pool experiences heavy usage, especially during hot weather, more frequent visits may be necessary to ensure that the water remains safe and inviting.
5. Special Circumstances: Certain circumstances may require additional visits. For example, after a storm or heavy rainfall, the pool may need extra attention to remove debris and rebalance the water chemistry.

It's important to communicate with your pool professional and discuss your specific needs and circumstances. They can provide guidance based on the characteristics of your pool and local conditions. Regular maintenance from a professional firm like Pasadena Pool Cleaning and Repairs helps prevent issues, keeps the water clean, and ensures that the pool equipment operates efficiently.