Blood rings | Improper storage | Follow recommended egg storage and gathering recommendations. |
| Improper incubation temperatures | Check thermometer accuracy and incubator functions. Follow recommended temperature settings. |
| Improper breeder nutrition | Feed breeders a diet with balanced nutrient levels. |
| Improper fumigation | Follow fumigation recommendations. |
That is what I found causes bloodring, nothing about an infection.
As fr cleaning a styrofoam incubator I would try using a new sponge and antibacterial dish soap, but that's just me. I'm not anywhere near an expert.