Plant spotting and drying tips (newbie)

[swede888]

Hi, I am trying to figure out if the symptoms my plants are experiencing might be from too much light or too strong of nutrients or any other ideas? Plants have been in veg in hydro set up for about 3 weeks. I have been having a lot of problems with leaves developing spotting and the tips drying with eventually the whole leaf drying up.

Here is the setup:

Strain: White widow fem
PH: 5.6 to 6.0
Temp: 75 degrees
Humidity: 35%
Setup: DWC with 2 air pumps and 4 stones
Light: 400w digilux HPS about 12 inches above plants with 2 sun blaze fluorescents to provide extra blue spec
Nutes: Canna Aqua Vega following manufacturers instructions of 30ml/10 litres; 350pmm; changed reservoir 5 days ago.

Any help would be greatly appreciated. This is my first grow, I was hoping to avoid problems, but no such luck.

 

[Dan Ultra]

What type of water are you using? RO? Looks a little like a Cal/Mag deficiency.

 

[swede888]

I was using tap water. It was about 40ppm out of the tap.

 

[BuddroGreen]

Looks like Cal-mag, especially with only 40ppm tap water.