Phal Germinating Seeds turning Black

[DozerDC]

Hello all - first, thank you to all the forum users and posters here as I have found this forum to be a wealth of information as I continue my adventure in orchid propagation from seed. This adventure has been so much fun despite tons of set backs and failures.

Using this forum, I also think that I know the answer to my question: why are my precious little babies turning black? I tried to get a good picture; the attached isn't very good.

I flasked some phal seeds back during the eclipse on August 21st. There was no contamination in the jars but now just as the seeds are now turning green and little roots are visible with the help of a magnifying glass, some of them are turning black - I should say the agar underneath of them is turning black. I assume this is not good as it isn't a dark green, but is just black. Death black. Reading on the forum here people seem to indicate that it is a reaction to phenolic compounds that the protocorms are producing.

If this is indeed the issue how can I prevent this? I read some people say to mix activated charcoal into the agar. But then some people say that isn't true and that it won't help. So I would love some verification. If the charcoal will help, can someone be kind enough to point me to the right charcoal? Also, I read that if you add charcoal to the agar that you have to do special steps to prevent the charcoal from settling to the bottom of the jars. Lastly, is there anything I can do at this point to rescue this batch?

Thanks!