A useful answer starts with understanding your pool. Share what you know; you do not need to have every measurement before asking.
A starting template
My region and climate: a broad location is enough; please do not publish your street address.
My project: a new build, conversion or existing natural pool; approximate size and age if known.
My stage: exploring ideas, planning, building or maintaining.
What I would like help with: describe one main question or the change you have noticed.
The current arrangement: describe the filtration, circulation, planting and equipment you know about.
What changed, and when: include recent work or observations that might matter.
What I have already checked: include the actual readings, units and dates if you have them. It is fine to say that a detail is unknown.
Photographs: a wide view and a closer view of the relevant area are often easier to understand together. Share only photographs you have permission to publish and avoid personal details.
Keep the conversation useful
Explain what you are trying to achieve and ask for clarification when advice assumes something different. When you try a suggestion, return to the same discussion and describe the result. That update can help the next person with a similar question.
A discussion can help identify questions and next checks. Project-specific design or safety decisions may need someone suitably qualified to assess the actual site; a photograph alone cannot establish those facts.