Problems with SH- grow room details inside. PLEASE HELP!

[Ray]

Maybe I am misunderstanding you, but what you just described sounds pretty standard.

The scenario you mention about the old roots plumping up and turning green is an indication that the velamen is becoming saturated and translucent - as expected. That does not mean those roots are well-suited for staying that way, so the fact that they die is also to be expected - as it the fact that the new roots grow down into the reservoir.