My last hatch I got 20/25. This time things don't look so good. So far only 4/32. I candled on day 16 and things looked ok. I have four breeds in the incu and only 2 EE and 2 friz have hatched. Others have started and quit or so it would seem. I did switch 13 to a still air 1602N and some have pipped but still no chicks. Mostly Dels and I know they were fertile. One did pip and looked like it was "leaking" but on inspection there was a live chick. Nothing since. In the Gen 1588 which was running low compared to the last hatch there are 4/19. A few pips but nothing. Today would be day 21. The thing is I have Dels, friz, EE's and bantam Brown leghorns. Only 2 Ee's and 2 frz's have hatched. I would expect some Dels to hatch and the leghorns too. I know their fertile. So what could be the problem?. Last hatch i did set the eggs up in a carton, but didn't this time cuz I thought some had a hard time getting out. 5 of the 25 had to be culled. The incu did have some problems in that it made a funny sound like a revving engine, like it was straining, kinda like a car that sounds like it's going to stall. I did call the GQF folks and they sent me stuff but I was in the middle of this hatch and I've had hatches run low before and I got better hatches than this time. Hum was ok. What causes chicks to quit when pipping? Eggs I got it's the time and monitoring.