Finally have the tank on the stand with water running through for the first time. Just doing an equipment and leak run. It's a 120 g with two corner overflows in the back. I was at the LFS
and noticed something. On their system the level behind the overflow covers stay the same height. On mine it seems to be rising and falling about 1-1/2" every minute or so. Tank level and sump level are steady. Is this normal? Will that settle over time? Should I just keep an eye on it? Thanks so much...