Help guys! Northern Lights, Super Skunk (PICS)

Hello.
I'm using White Label Seeds. Feminised SUPER SKUNK and NORTHERN LIGHTS.

The White Label Seed Company > Feminised Seeds

Started from seed on 23rd of march. 28 days

Used 400w HPS and now 24h ago switched to MH.
Temperature is 24 - 27 C when the lights are on. 20 - 22 C when off.
Humidity 40 - 50%
Using biocanna nutes 1/4 strenght.
PH adjusted tap water.

Now I'm not using any nutes for last two waterings. Just PH balanced water, but it is still getting worse. Any ideas?













Thanks for any help!
PEACE!