Using hose water is a bad idea, too many contaminates. That's why it's not supposed to be used in the battery. Distilled water is the only water to use.

Required coolant mix from the service manual. Distilled water is specified. It's cheap at Wally Mart.

Use coolant approved to MB 325.0, such as Mopar part number 05066386AA, or an equivalent Extended Life Coolant
with the Hybrid Organic Additive Technology (HOAT) inhibitor system.
The cooling system is designed around the coolant. The coolant must accept heat from engine metal, in the cylinder
head area near the exhaust valves and engine block. Then coolant carries the heat to the radiator where the tube/
fin radiator can transfer the heat to the air.
The use of aluminum cylinder blocks, cylinder heads, and water pumps requires special corrosion protection.
MoparT Antifreeze/Coolant, 5 Year/100,000 Mile Formula (MB 325.0), or the equivalent ethylene-glycol based coolant
with organic corrosion inhibitors is recommended. This coolant offers the best engine cooling without corrosion
when mixed with 50% ethylene-glycol and 50% distilled water to obtain a freeze point of -37°C (-35°F). If it loses
color or becomes contaminated, drain, flush, and replace with fresh properly mixed coolant solution.