IN NEED OF HELP. Is this a Manganese deficiency? or something else

[goroth]

HELP!!! I am in my 5th week of flower. Growing Aurora Indica in soil under 400 watt HPS with GH nutes. I was extremely happy with how flower was developing until these spots showed up a week ago. They are brownish/grayish in nature and the affected leaf eventually starts to curl up. I cant find any similar pictures on the internet, the closest thing I could find was a Manganese deficiency. I flush a 6.5ph and that seem to have not helped at all. I NEED HELP!!! Can anyone point me in the right direction?

[CaptainWiese91]

Do you have more pictures in normal light ?
what type of soil are you using ?
What about nutrients? How much and how often ?
What type of water do you use ?
Is the PH levels only 6,5 when you flush or is that PH levels ever time you water/nute feed her ?

[goroth]

Here are some different pics of the problem. This is actually on 2 plants and just starting to show signs on a third

Soil is FFOF
GH nutes at 1/4 strength which came at the recommendation of several grow journals
I feed about twice a week then water with recharge once. Soil is dry to the first knuckle every 2 to 3 days
Water is de-chlorinated tap water with about 90 ppm out of the tap
I have been watering closer to 7.0ph

[Tersky]

I'd say ph or root issue. 7 is high and you could be running into some deficiencies. Check this chart:

[goroth]

Thanks Tersky. I am gonna run out and invest in a PH pen today. I have been using the GH drops kit which I havnt really had an issue with until now

[Tersky]

Yeah i used the drops for years. I got a ph pen for my last grow and it makes it easier to tell exact ph. Granted you do have to maintain it and re calibrate it every so often but imo worth it. Also the light you look at those drops in matters. For example if looking at sample under HPS it will make it look yellowish. Hell even soft white house bulbs can give it a warmer tint. Here is the pen i use. It works and is cheap. https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

[goroth]

Is anyone else able to weigh in on this? Flower was really starting to look nice and I would hate to stunt progress anymore than it has been?

[UndergroundFarmer]

I use a pH probe for my stuff in coco and it is a lifesaver. I'd say the pH is out of whack or possibly has been changing too fast for the plants' liking just from the look of it. Most of my growing is hydro so I'm still learning how to handle trouble in soil/coco. Luckily, there hasn't been much. (I'm looking at you, Blueberry!)