Hi, so checked out your pics, do you have alot of flow in your sump and do i need a light and fan if not running cheto and if i want to run cheto where in sump would i put it. I don't have alot of room in the sump. when i get home i will try to take a picture and post it.

sump
 

I think if you went with a bigger sump or a bigger area that your pump is in that will help. Im assuming your pump is pumping most of that water out and takes a while for that water to make it back so there for your pump runs dry.

how is your sump set up? How many chambers?

there are 3 chambers in sump
1st on right side is under overflow and i have a filter sock the water flows into. i also put some small rock in this chamber
2nd has the sump in it
3rd has the return pump