Hi all, I hope this works as this is the first time I have uploaded a video I'm not sure if this is normal and has always been happening and I just haven't noticed? Or something is wrong with my system? I noticed today that when I turn off my RO system via the control unit the very first pre filter the one the tap water goes into first drains down about a 3rd of the way? Then when I turn it back on fills up again to the top and starts the filtration process . As always your advise is very much appreciated.