Proper sump water level?

I have a Aquaclear 75 sump system that came as a kit. My question is what should the proper water level in the sump tank be. There is a marked water line, but that puts the water level just below the top of the return pump, and when I do that it injects all kind of micro bubbles (of air I suppose) out of my return nozzle into the fish tank. So when I raise the water level so the return pump is completely submerged it appears that the path of water flow trickling down thru the pads and bio is not following proper path and just flowing across instead of down ,up, and over.....if that makes any sense?

 

Is your filter pad not letting the water flow through them?

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The water line needs to be enough to when you have a power outage, the water returning to the sump does not overflow. And also, when running normal, the water usually doens't run through the pads correctly. You have it adjusted correctly when you have the pump totally submerged, it should not be anywhere near above the water line.

 

this is the right stuff

 

When you refer to the "pads" are you referring to the top level where the large sump hose comes down from my overflow? Because under that 1st tray is the second level which is packed full of bio-balls. then the 3rd level under that is where the water comes down into and the goes over a little ledge comes up thru a large pore sponge (to eliminate micro bubbles) and then up and over a short ledge and into the sump tank where the return pump is.
Right now I have the pump fully submerged and all is running fine and quiet with decent flow coming out of the return head. I have also checked with the powere off and
I do not come close to overflowing my sump tank. So it all seems good. I was just questioning this because it seems that my main water level in the sump tank now is actually up to the bottom of the second level where the bio-balls are. It is not allowing it to trickle down from there. Maybe I am just over thinking this thing!

 

Over thinking. Its right where it should be, some of the bio-balls will be within the water line. Sounds like its dialed in to me, maybe a bit low, but your in good shape.

 

I think I'm ok too. But here are a couple of photos. My mistake, it is a Aqualine brand sump setup. The little blue sticker on the middle right side of sump tank is the recommended water line I was refering to. That seems to be way too low for the return pump they provided. I do have it on the rubber suction feet to eliminate vibration noise, but that does make it sit higher.

 

Looks good from where I'm sittin. They were expecting a much small return pump in there, considering how low that water line is.