Last week I noticed the leaves were starting to turn upwards on the tip and getting brown in color (also on the tips). I flushed the system and added nutrients afterwards as I usually would. Three days later or so two of my plants began to wilt and the stems are turning purple. Now I notice stems starting to turn purple on the rest of my crop and leaves starting to droop. Is this simply overwatering. I am growing in rockwool and was watering once a day using the GH flora series nutes and a ph of 5.8-6.0, they are now in week 6 of the grow. The plants have gone without water now for about three days. Could it ba a nutrient lockout of some kind combined with underwatering? I was thinking maybe I mixed the solution wrong by not adjusting the ph right and after flushing they never got replenished with nutrients because of a possible lockout. Any info would be helpful.