Save my plants!!!!!!!!! (pictures)

I'm having a few problems as all newbies do. Please help me same my plants.

Problems

Problem 1

Very stunted growth

Problem 2

Yellow lower leaves

Problem 3

Droopy leaves

Problem 4

Pale green leaves

Problem 5

Curly bumpy leaves one plant. droopy yellow leaves on another

Details

Ebb and flow hydro system
Nute tank full of Rainwater + hydro nutrients
Watered 3 times a day
400w HPS light(18hrs a day)
PH 5.9
Rockwool grow medium

Pictures

james622 said:

Problem 1, Very stunted growth, Problem 2 Yellow lower leaves, Problem 3, Droopy leaves, Problem 4, Pale green leaves, Problem 5, Curly bumpy leaves one plant. droopy yellow leaves on another
Ebb and flow hydro system
Nute tank full of Rainwater + hydro nutrients
Watered 3 times a day
400w HPS light(18hrs a day)
PH 5.9 Rockwool grow medium

Click to expand...

are these blueberry? bb is famous for having early deformed growth. stunted growth, how old are they? they look like you need to bump up the nutes. you should be around 400 ppm. this will take care of the color problems, they're a bit hungry. ditch the rain water and use r/o. rain water is full of dirt and pollution. i like a ph of 5.8 myself.

The deformed one is a mango strain. I have no idea what the pale one is. The nutes are at recommended strength. PH is 5.8. They are about 4.5 weeks old. I may switch to tap water. I still have no idea why im getting poor results.