Nitrogen deficiency in flower?

First outdoor grow. These are in soil in 15 gallon fabric pots. Started flowering about 4 weeks ago. I was travelling a bit so up until this last week they were only being fed about once per week. It's hot here 85F-95F so lately I water them basically 5 gallons each every other day.

I've noticed within the past couple weeks some lower fan leaves started to yellow and fall off, it has since gone up the plant a bit, but still just the older fan leaves. I'm starting to feed them every other water now, so roughly twice a week (just started this week). Should this be enough to fix this? Overall the rest of the plant looks pretty healthy, but still losing leaves pretty quickly.

Stats:
Using GH FloraMicro & FloraBloom
Using the Lucas formula - 8mg Micro and 16ml Bloom per gallon.
Puts water at roughly 900 ppm on a .5 conversion. Water at 6.5 ph

Plants will just shed some older leaves naturally through their cycle. You may a have a slight nitrogen deficiency. If you do anything, I wouldn't go overboard.

N of 5..... No N def.

Basic normal plant progression for the feed ratio's given.

Looking good. My outdoor plants get more yellow leaves than the indoor plants. I run the same feed on all my plants. I have added the Grow only rarely and then just a half teaspoon in 5 liters of water.