Something missing on overflow pip?

[fish]

I'm trying to put overflow pipe between sump tank and grow bed. (Fish tank > Sump tank > Grow bed)
Sump tank is lower position than Grow bed.
Initially, I tried a overflow pipe which output pipe is higher than overflow in the water. It didn't work.
So, I tried to make basic pipe first. But it doesn't work either.
The bottom of pipe in water is slightly higher than outside pipe. Should I change to much higher?
or anything missing or wrong with this piping?
Before starts experiment, should I put the water in the pipe? (I did but the same result, no syphon movement or anything. just nothing happen. I pumped water to the container where the overflow pipe located to make sure water is pushing.)
All of the pipes are 1 inch dia.