This is concerning. How is water returning from the tank to the sump? Most people use some sort of overflow or siphon. The nice thing about an overflow or siphon is that it will always adjust it's flow to match the incoming flow. (unless it hits it's maximum flow)
If you have an overflow running, the only way you can get into the situation you describe is simply not having enough water in the system.
If you actually had a situation where the sump pump was outpacing the return...then you are headed for a tank overflow.
40 Gal Hex, 10 Gal Sump, CPR overflow with Mag 7 return, Maxxima 35 RO
, 10K MH
pendant, 2 x 15W actinic, 1 yellow tail damsel, 1 high fin goby, 40lbs LR
.com rock, 1 red head goby, 1 algae blenny, Leather, blastomussa, sun, and hammer corals, green polyps, carpet anemone, 2 sexy shrimp...and more LR
critters than you could imagine in your worst nightmares.... Mantis in 5 gal