Sick Looking Leaves. Help!

[Dieselpower]

Hi there everyone!

Northern lights automatic
Nearly 6 weeks from seed
Lite soil
300w dual spectrum cfl
~23degC
~40% RH
Biobizz grow, bloom & topmax at half strength
Spotted the spots on the leaves today. Any ideas what it is?

Help would be awesome :)

Thank you!!!

 

[CaliRooted]

Looks like maybe Cal. First what's your PH?

 

[Dieselpower]

I've measured my runoff water at ~6.3.

 

[Dieselpower]

I have literally just Watered it as it has been about 4 days and the pot was bone dry

 

[CaliRooted]

Whole plant pic would be nice if ya can.

 

[GT21]

Take a picture of the main stem

 

[Dieselpower]

Here is the whole plant :)

 

[Dieselpower]

This is the main stem :)

 

[GT21]

This is the main stem :)

Up a little more.... are you finding purple stripes on the stem?

 

[Dieselpower]

Not on the stem. There are reddish purple streaks on some of the branches though

 

[GT21]

Not on the stem. There are reddish purple streaks on some of the branches though

Thats usually the start of phosphorus problems... i would bet your ph is off or you need to boost pk
Start by checking your runoff ph

 

[Dieselpower]

Thanks buddy!

Sounds like I'd better get myself a better soil ph tester then huh?

 

[Dieselpower]

Could someone please tell me how I would go about adjusting my soil ph at this stage of a grow? I have bottles of ph up and ph down. If the ph was say 8 would I be best off mixing some plain water to a ph of 5.5-6.0 to balance it? Or am I ridiculously wrong?