If you are not sure in something always check it. For example when your pH value is not with the expected value, search for the problems, always ask yourself a question when something isn't working fine, where is the problem. Always update your knowledge, you never know when something will be useful to you. Is always good to make reminders to not forget something. Don't talk too much about what you are doing to your boss if he is not familiar with your job, because if he is not he probably will remember only one word from what you are trying to explain to him and that can lead to big misunderstanding and big loss of money, so don't explain all the stuff of what are you doing to your boss. Always expect and calculate the worst scenario. Always think about the consequences that can happen when you make some changes(even if they are minor). If you are not sure about something you are going to do, consult with the other engineers or persons which can you provide some advices or help (2 heads are better than one). You need to have clear pictures in your mind of what you are going to do(change). Always think before act.
Best Regards,
George