Here are some pool construction companies in Istanbul that you might consider:

1. Polin Waterparks and Pool Systems

• Services: Waterparks, pool construction, water slides, and aquatic attractions.

1. Çekiçler Havuz

• Services: Pool design, construction, maintenance, and renovation.

1. Pool Art Havuz

• Services: Custom pool construction, maintenance, and water treatment solutions.

1. Vikoma Havuz

• Services: Pool construction, accessories, and maintenance services.

These companies offer a range of services from design and construction to maintenance and renovation. It’s a good idea to visit their websites or contact them directly to get more detailed information and quotes for your specific project.