The water level will not go up to the float. If you have just installed the system, you should have added a couple of gallons of water to the brine tank prior to putting it into regeneration. if you didnt, it may run slightly short the first time. After that, the system will be fine. Your system should only add a few gallons of water the brine tank, the float is only a back-up in case the flapper valve fails, or there is a power outage during the refill cycle.
Hope this helps.