Damping-off is actually caused by many different organizms, damping-off. Trichoderma harzianum Rifai strain KRL-AG2 (RootShield®). This fungus is awesome - it does a pretty good job protecting plants from organizms that would otherwise cause problems. You should read about how it works --> (RootShield®)
Just because you can see visible fungal hyphae, does not necessarily mean you have a pathological organizm, micro-flora are quite dynamic.
Joseph Clemens
Tucson, Arizona, U S A