Dodge ram 1500 2001 5.9 l what do I do surely my system requires more fluid water etc ..
Realistically, you need to get more coolant. What you have right now is 50/50 (50% antifreeze 50% water - otherwise known as "premix"). 50% antifreeze is the minimal amount of antifreeze your cooling system can work with in cold weather. If you put more water into the system, it will freeze and cause damage to your engine and cooling system. The only solution is to purchase more 50/50 premix and fill the system up.
Although for best protection, you must use 50-50, I have used much more dilute in emergencies. As long as there was a decent amount of antifreeze in the water, it only froze into a slush and didn't burst anything. It won't freeze while it's heated up driving. In newest engines, they run at higher coolant pressure, and I would be more worried about boil-over warmed up. It's a whole other story at very low temps like -18F.