1. don't use RO water, it removes all your necessary minerals (calcium, iron, magnesium, potassium, etc. etc. ) ... that all has to be replaced, for healthy plants ...

2. don't use fertilizers, until after your clones are fully rooted ... also, this is where low light levels help (rooting) ...

3. throw away the damned Superthrive, that crap has killed more plants, than I can count ... anything beyond 1-2 drops per gallon, is TOO much ...

4. rockwool has to be fully treated for days, to stabilize it's pH (I don't use the stuff, just for that reason, I prefer RapidRooter bark plugs, already pH stabilized) ...

hope some of this helps, good luck ! :thumbsup: