**3.2 Test solution**

The study test solution was tropical seawater collected approximately 100 m from the shoreline of Pantai Teluk Kalong, Kemaman, Terengganu. Pantai Teluk Kalong is located near Teluk Kalong Industrial Estate (oil and gas industrial area) and Kemaman Supply Base port which is about 6.78 km from Chukai, Terengganu, Malaysia.

Pantai Teluk Kalong was selected in this research due to widely application of Al-Mg-Si alloy in the shipping, marine, oil and gas industrials surrounding the area. The values of physicochemical properties of seawater such as salinity, dissolved oxygen, pH and temperature were monitored during the immersion test. Average selected physicochemical data of the seawater used are reported in Table 2.


Table 2. Physicochemical properties of seawater
