Compare the color of the sample with the color chart that came with the kit. Matching colors will tell you the pH of your sample. The better kits will also advisory booklets about how to interpret your result. Look under Fertilizing Bougainvillea for infomation about why ph is so important. Some commercially prepared growing mixtures have an added wetting agent which is a great help when it comes to planting and watering.
Polymers are nontoxic and last for a number of years before breaking down in the environment.
In North Flordia, pine bark is a cheap and readily available ingredient. The amount of lime added was always based on soil testing and it varies. Pulverize any large lumps or clods as you mix. When thoroughly mixed add sufficient water to moisten the mixture and store in a sheltered spot until you are ready to use it. A garbage can, wastebasket, or large bucket makes a handy storage container.