If you have a dirty pool, the cost of cleaning it can vary depending on how bad your situation is. A one-time service might run around $75 to $100 per hour and require two to three hours. Hiring a professional pool service to clean your pool weekly will usually cost between $125 and $300 per month. If you only require a one-time cleaning for a pool party or other special event instead of a regular monthly service, you would expect to pay $120 and $350 for a single service call. However, if your pool is filthy or “green,” expect to spend $300 to $500 on the initial cleaning. And $120 to $175 per month for upkeep costs. Prices depend on the size and type of the pool.