Definitely do not rely on the panel. First time I stayed at a State park w/o a water hookup, my panel showed freshwater 1/3 (50 gal tank). Freshwater fill station was 100 yds away. So I filled a 1 gallon jug, went back and forth 5 times (5 gals). Checked panel and it says full. Iím going to get a 19.99 flow meter to measure fill up. Iíve owned 6 RV camping units over past 35 years. This was the first time I used the fresh water tank ( yes, I flushed it out at home before filling). I already had previous experience knowing black and gray guages were little more than guesswork and not reliable. I did locate the pump and intake tube coming from the tank. It was 3 inches short of bottom of tank. So in a 50 gallon tank, that much water in the bottom is unusable unless you access through the drain.