I have no idea, please help

Guys I'm happy to report every thing is looking much better. Leaves are all up nice and perky. New growth the stems are no longer woody and thin. Can actually pinch to super crop the new growth. The worst one of the lot which I posted here which had droopy leaves. She's now got all her leaves up and all look a much better shade of green.

Should I use the Epsom salts again? Going to flower these in one weeks time. Should I just leave it and simply water now knowing the ph is correct. Thanks for much for the help from everyone appreciate it and proper happy its fixed and still got to keep my plants.

do it once a week through week five of flower spritz here and there.

So imagine this...back with the same problem again...and even the same cause. Ph pen was out, despite calibrating it and it reading on point to show 7 with the buffer. Anyway same problem, red/purple branches that are woody. Try to super crop and the branches just snap.

Last time I sprayed with Epsom salts and sure the next day all the leaves was lovely and dark and purple stems gone. Well that hasn't happened this time. Sprayed them and they look the same. Frustrating as that fixed it last time? I have put on the second 400w just to speed up the pots getting light enough to give the ladies a feed. Then they can get a feed with the correct ph and see how they look. Also gonna bump up the feed a little as they deffo could be on a higher ec at this stage.

Anyone else not seen the results from using Epsom salts straight away? If so then should it be okay to use epsom salts for a second time a few days from now? It honestly was all I done last time and if cured the problem. It 's the exact same symptoms, red stems that are woody and pale green looking leaves.