Im having a clone/ EZ clone issue

I just put 65 clones in a EZ cloner that I built. I filled it up & took off for a couple days. It seems that a lot of the water evaporated to the point that it wasnt spraying like it was supposed to. They look healthy but they all seem to have a blackish color forming at the fresh cut.. Does anyone know what this is?? What cause's this? & how do I treat it?

The clones have been in it for 5 days.
PH is @ 6-6.5
ppm 300
room temp 70
water temp 73
humidity 65%
diped in rooteck befor going into EZ cloner

Are my girls goin to die?

Sounds like mold or rot. When you put the clones in, you left an inch or so under the collars? Also, were you careful in not choking out the clone when you pushed the neoprene collar down?

if in doubt and you have enough stem get a clean blade and recut

This happened to me the first time. I pushed the neoprene down to make it nice and snug and it choked out my plants, they rotted from the collar up, turning black and slimy. All dead, next time I learned not to smash the stem but just enough pressure to hold it still

Thanks for the info! I'll give it a try & get back to you if the results are good..