Thanks for the advice guys. I'll stop spraying the leaves. I think I found the problem. It could have be K and Mg for all I know. I think the PH was locking up the nutes. Once I dropped it down the problem stop progressing. The res PH was 5.9-6.0 but when I check the run off PH it was a bit higher. Once I flushed the rockwool with PH around 5.6-5.7 and made sure the run off was the same the plant perked right up.

Thanks again.