Marijuana grow tent problems

A question from a fellow grower:

We have developed a problem on our 2nd grow . We are new to this . We
purchased Super skunk and White widow . We are 84 days into veg. No
room in the bloom room to put them to bloom . We have them in 5 gal
buckets with 6 to 8 drain holes in each bucket . The Ladies are
growing in coco soil (rg basement indoor/outdoor soil ). We have
fertilized with miracle grow 15-30-15 at 1/2 strength per gal. and
fertilized each plant 27 days ago with a 1/2 gal . Our water schedule
is 1 half gal of untreated well every 4 days . We are growing in a
4’x4’x6’ grow tent , our lights are 4’ 8 light t5 ho’s . we are on a
18/6 light schedule . Our average temp is 66 to 72 degrees .Our
humidity is 59 to 75% 1 day after watering we have included some pics
. that show the issues we are having . We tested the soil ph value and
it was 7.4 and 7.3 . the 2 plants that are shown are displaying what
looks like 2 different conditions to me . Any suggestions would be

The pics didn’t, or are not present at the time of this response from me.

However, a pH of much above 6.5 will cause problems. I suspect the well water may be a contributor.

You want the root zone in the soil at 6.5, or relatively close and certainly below 7.0 if at all possible, otherwise you will start to have nutrient availability problems, lock-outs or toxicities. And so you need to also make sure your fertilizer/nutrient mix, as well as your plain water is at 6.5 at every watering and every feeding.

6.5 should be your target pH in soil and if you have a high concentration of coco coir, it is almost more like hydro and would likely be ok to as low as 5.8, the target for hydro. But you want to make sure it doesn’t ever get below 5.5 nor much above 6.5