If you’re buying an older home in the Houston area look out for old galvanized plumbing supplies. Galvanized supplies can rust from the inside out reducing the inside diameter of the galvanized supplies. This decreases the water flow making it diificult to produce a functional water flow,  when one or more fixtures are in opearation. The low water flow is a sign that your galvanized supplies may be reaching the end of there life span. Brown or redish water that doesnt run clear after running water for serval minutes may also be an indication as well. Galvanized supplies rust at joints at connection . Old galvanized supplies with these types of conditions are leak hazards. While observing these types of conditions during your home inspection.. I would recommend a plumber evaluate and give estimates of replacing the old galvanized supplies. This can cost thosands of dollars  and water damaged if left unchecked.