About testing, the best is to test as many times in the day as you can. This way you will learn by yourself and make good sense of the cause-effect.
The first urine pH in the morning is the most important, because it says the most about the real pH of the fluids and tissues of the body (since the morning urine has been in contact with them for many hours). Naturally, this morning urine pH figure is the hardest to get alkaline.
Citrus fruits are very cleansing and can leave very good alkaline ash in the body. Just try no to take too many in the beginning.