The expansion of global seaborne transportation has created a massive undertaking in formulating ballast water management protocols that include pH and a host of other water quality measurements. Ballast water is the most common way for ships to adjust the way the vessel floats and is balanced in transit, especially when cargo has been emptied. The proper treatment of ballast water is critical to safeguard local environments. The purpose of this treatment is to mitigate the introduction of non-native organisms including fish, plant life, and microscopic organisms. The monitoring of pH ensures ballast water treatment processes are both efficient and effective. Ballast water applications measure pH in process and in the lab using grab-sample methods. Typical ballast water ranges from 6 to 9 pH. Cold samples and high levels of salinity can compound the difficulty in measuring pH. These challenges can be mitigated with the optimal sensor design, in particular the reference junction design, housing material, and sensing chemistry.