Please Help Identify The Problem (pics)

First, the plants are generally healthy. They are growing rapidly still, in week 3 of flowering. Pics below are from leaves towards the bottom, except the one showing the leaves curling under themselves (that one is from mid-plant).

There are different things going here... but could this all be magnesium deficiency?

Here is some other info:

Grown in Soil.
How long has this problem been going on? - 3-4 days
What STRAIN are you growing? - Sativa (unsure of exact strain)
What was the establishing technique? (seed or clone?) - Seed
What is the age of your plants? - 11 weeks
How long have they been in the soil mixture they are in now? - 10 weeks
Were they in the same mixture when they were seedlings/smaller plant? If not, what mixture were they in before? - They were moved to this soil when transplanting from small cups at 1 week
How Tall are the plants? - approximate 42 inches
What PHASE (seedling, vegetative or flower) are the plants in? - 3rd week of flowering
What brand Nutrient's are you using? - I'm in Europe, so the brands are different.
How much of each nutrient are you using with how much water? *Knowing the brand is very helpful* - Mix has 4% Nitrogen, 6% Phosphate, 6% Potassium Oxide, small amounts (less than 0.01% of each) of Iron, Boron, Copper, Manganese, Molybdenum, & Zinc. Using 5 ml of solution for every 2 liters of water.
How often are you feeding? - once every 5-7 days (when the top few inches of soil are dry)
If flowering, when did you switch over to using Bloom nutrients? - first watering after switch to 12/12, which was 3-4 days into week 1 of flowering
What is the pH of the "RUN-OFF"? - Soil pH is 7.
What method of pH test was administered? Using Strips? pH pen? - pH meter used to measure soil pH, when soil is wet.
What is your RH Factor? (Relative Humidity) - Low humidity
What is the Day/Night Temp? (Include fluctuation range) - 75/68
What is the current Air Flow? (cfm etc.) - growth area is large, no mechanical system in place for air flow.
What water are you using? Reverse Osmosis (RO)? Tap? Bottled? Well water? Distilled? Mineral Water? - Filtered through Brita
Has plant been recently pruned, cloned or pinched? - No
Have any pest chemicals been used? If so what and when? - None
Are plant's infected with pest's? - No


Thanks in advance for any help.

Usually around week 3-4 in flower you are going to start seeing evidence of deficiencies like this. It appears as if it is in the start of problems with phosphorous, Ca and Mg. On the other hand, it looks like the plant might be getting too much nitrogen. Can you go into some detail about the grow? Type of water, soil, temps, nutrients, PH, ppms, etc....

Sorry - More info below:

Grown in Soil.
How long has this problem been going on? - 3-4 days
What STRAIN are you growing? - Sativa (unsure of exact strain)
What was the establishing technique? (seed or clone?) - Seed
What is the age of your plants? - 11 weeks
How long have they been in the soil mixture they are in now? - 10 weeks
Were they in the same mixture when they were seedlings/smaller plant? If not, what mixture were they in before? - They were moved to this soil when transplanting from small cups at 1 week
How Tall are the plants? - approximate 42 inches
What PHASE (seedling, vegetative or flower) are the plants in? - 3rd week of flowering
What brand Nutrient's are you using? - I'm in Europe, so the brands are different.
How much of each nutrient are you using with how much water? *Knowing the brand is very helpful* - Mix has 4% Nitrogen, 6% Phosphate, 6% Potassium Oxide, small amounts (less than 0.01% of each) of Iron, Boron, Copper, Manganese, Molybdenum, & Zinc. Using 5 ml of solution for every 2 liters of water.
How often are you feeding? - once every 5-7 days (when the top few inches of soil are dry)
If flowering, when did you switch over to using Bloom nutrients? - first watering after switch to 12/12, which was 3-4 days into week 1 of flowering
What is the pH of the "RUN-OFF"? - Soil pH is 7.
What method of pH test was administered? Using Strips? pH pen? - pH meter used to measure soil pH, when soil is wet.
What is your RH Factor? (Relative Humidity) - Low humidity
What is the Day/Night Temp? (Include fluctuation range) - 75/68
What is the current Air Flow? (cfm etc.) - growth area is large, no mechanical system in place for air flow.
What water are you using? Reverse Osmosis (RO)? Tap? Bottled? Well water? Distilled? Mineral Water? - Filtered through Brita
Has plant been recently pruned, cloned or pinched? - No
Have any pest chemicals been used? If so what and when? - None
Are plant's infected with pest's? - No


I hope this is enough info... thanks again.