Are they staying too wet in the rockwool? I'm not experienced with it but I have heard it is very easy to overwater in rockwool.

In the meantime, I suggest you KISS:

1. Lay off the Sugar Daddy and any other suppliments until you have a handle on what's going wrong. Regular nutes and pHed water only.
2. Don't make a bunch of changes at once. Troubleshoot one thing at a time and give your plants time to respond before doing something else.
3. Search the hydro forum for 'overwatering and rockwool'.

Time for some of the hydro folks to chime in...

ipe: cb