Overflow problem, any engineer out there?

[Coleus]

So i plan to have my sump in a different room with my tank. The problem is the pipe that connecting overflow and sump wont be a straight downward slope. it will have to some minor upward slopes to get around the bathtub sitting in the middle, will this be a problem? Will this cause my water to overflow eventually.

I had a similar smaller setup before and where the overflow line has to go down and down and then go into sump. The highest point of pipe still much lower than the water line in my tank. But occasional i got the overflow problem. I never caught it, just got home and water is on the floor so i suspect that was the problem because the air get into the tube and it needs enough pressure to push that air. Is my theory correct?

Thanks