Hiya a45man, hope you manage to save em..
Question: Why did you start giving the Ladies
"virikop"(treatment of broad spectrum fungicide and bactericide)
And I can't comment on ~
"wonder surranure plus[3:2:1]
I've Never used it.Is that Fan Blowing straight up @ 400w Hps? then where does you built up heat go?(do you leave door open during Lights On) also what about your placement of Other Fans? where are they...
From the Look of Pics..I would say you been training the Ladies(The white string)...
What kinda Soil/Compost did you use...Most feed Plants for first 4-6 weeks??
My thoughts(could be wrong)
The Pots are too small now for Ladies(Might be a little pot-bound) 6" is not a lot of space/room and with smaller pots means more waterings...
Do you have Perlite in your mix?? IF not buy some and while you at it get some soil/compost(seedling Compost) sit in a BIG pot and pour loads of water through the Compost a few times then let go nearly dry(Put in cupboard nr Fans n Heat) when dry but still a little moist..then add the Perlite and mix in well(you want IDK maybe 60% Perlite + 40% Compost/Soil..next get some Pots that are at least 15-20 ltrs 3-4 Gal at least, then you won't have to pot-on again..though that depends on Veg time...Bigger Pots can help with a Longer Veg..from what I've read...Its so many Gal per month??? you can Google this.
So fill up ya BIG *new POTS with the Mix you made Seedling Compost + Perlite(The Reason I suggest Seedling Compost and Flushing through lots of water is
(a) Seedling Compost is more delicate and contains Less ADDED feed/Nutes
(b) And by Flushing(this will remove a lot of this ADDED Feed,though not all.
Then be patient let they Ladies enjoy new home, don't water unless they really need for maybe 5days at least if unsure put your Little finger in soil(1-1.5") at edge of Pot, If Compost/Perlite bits stick to your finger...leave her..wait another day...
After a week or so in *new BIG pots they should have started to Perk up...
Do you check Humidity and Temps for Lights on and Lights off?? or are ladies under light 24/7?? I do 18/6 gives em down time(Rest) and saves on Leccy.
Peace