Please help with plant issues

Hello everyone. I’m having some issues with my current grow. I switched from de lights to gavita 1700 e led. I got 4 of these leds over 4 4x4’s and 9 plants per light. Growing in fox farm ocean Forrest soil in 3 gallon pots, watered every other day. The plants looked really good until a week ago some of the plants started having lighter green color on the new growths. Now the tops are yellowing and the top half of plants stems are purple. Can anyone help with what this might be ?
Strain- kushmints
Soil- fox farm ocean Forrest
Nutrients- floranova grow, no more than 4ml per gallon
Water- R/O

In short it's the led's "LED Deficiency"
The short answer your gonna get will be:
Raise room temp into the 80's
Increase light distance to canopy or dim.
Cal-Mag

OneHitDone said:

In short it's the led's "LED Deficiency"
The short answer your gonna get will be:
Raise room temp into the 80's
Increase light distance to canopy or dim.
Cal-Mag

Click to expand...

Thank you for the reply. There is 3 feet between canopy and lights. The lights have been dimmed to 50% since the beginning. Should I raise them more ?