The short answer is it depends. If you have a low flow rate meter then it may take longer than a higher flow rate meter. A good rule of thumb is to start with 5-10 minutes. Watch your flow readings to see if they seem higher than expected or if they are fluctuating. With low flows it may take 15-30 mins. Also, if you can vary the flow from low to high and back this will help to eliminate the bubbles. Proper orientation of the flow meter is also a factor, and in another blog, we discuss the influence of flow meter orientation. In most cases these methods will remove the bubbles.