Extreme newby here lol. I got the Aquatop 40g all-in-one tank 4 days ago and have had it cycling with just live sand for 3 days and yesterday added live rock and dry rock (even mix of both). My question is on the filtration specifically the return chamber. I’m not sure if this will be valid for all all-in-one systems or just Aquatop - up until today, the return chamber (the very last chamber where filtered water is pumped back into the tank) had a water level of about 1/4 - 3/8 full. Today the water level in that chamber is almost equal to the water line in the tank so significantly more full. My question is, is this normal? There is still a good flow from the return pump so it is pumping out. Is this just normal because there is better filtration through the sponge/biological filtration? Is the skimmer (which is making more bubbling noises today that before) messing up? I just want to make sure everything is ok but I don’t know enough about reef tanks to say as my only prior experience in aquariums has been smaller freshwater tanks with simple HOB filters. Thanks for the help everyone!