I'm looking for a reliable professional to perform regular maintenance on my small backyard pool. Tasks include skimming debris, checking and balancing chemical levels (pH, chlorine), cleaning the filter, vacuuming the pool, and confirming the pump is functioning correctly. The pool is around 20,000 liters, with a simple rectangular shape, and I prefer eco-friendly products when possible. Please include any recommended maintenance schedule and provide an estimate for a monthly service, as well as one-off visits if needed. I’d like a punctual contractor who can work around 10:00 and has basic safety equipment.