What is the fine-grained topic of the following text: Water: Adjusted with hydrochloric acid to pH 2.8-3.1 and supplemented with menadione sodium bisulfite (final concentration 0.4 mg/mL) to compensate for potential decrease in vitamin K activity upon autoclaving; water supplied in pinhole type bottles (Thoren Caging Systems, Inc. Hazelton, PA). Only return the topic.
Preparation and supplementation of water for caging systems