It's not recommended, but possible. The bag is heavy and large, not ideal for a hydration system. It's great as a pack shower when compared to other showers on the market due to its durability and roll-top closer. Using this has a hydration system would be difficult because it would not fit into most hydration sleeves and would most likely take up the whole pack (30L in size compared to 3L for most large hydration systems). The tubing is the same diameter as the MSR Hydromedary and Cloudliner reservoirs. --------------You really couldn't carry this as a hydration system. Besides all that stuff that Jason said, it'll weigh over 50 pounds and you'll never ever need that much. Horses don't drink that much.