Have a few plants starting yellowing leaves on the bottome leaves. One is worki g its way up to the middle. Need help deciding if its something going on or just normal. Week 3 of flower. Jacks 321 nutrients just as they recommend using. Flowers are looking good, packing on fast. Maybe the last picture of one plant having purple on edges of leaves is an indication?
Rh 48 to 55
Temp 72 to 80
Watering every morning aboit 1/2 gallon per plant. 7 gallon vivosun pots. Actually aboit 5 gallon soil.
Jacks 321,just switched to bloom for the 1 week
About to switch back to 321 as schedule suggests
Add silica every watering, add molasses on just water days
750 to 800 ppfd
Ph goes in 6.3 to 6.5
Im thinking potassium deficient?
Thanks!!!
Expect the lower leaves to yellow and fall off as the plant matures. It’s normal.
Agree with @MidwestGuy on the lower leaves and recommend a drench to drought routine with liberal run off. I read input numbers but nothing on the run off 
So water to a good amount of runoff and then let it dry out. Dryvout for how long? If i water in the morning to just starting to runoff it will be dry the next morning 1 inch deep. Should i let it go 2 days and dry out more?
Like i say they are flowering pretty good, even better than i expected them to. They stretched alot more than i wanted them to and got a little lanky. But they are bouncing back and looking pretty good now. Im just a worry wart and im sure i could be doing things better than what i am. Im completely self taught
It depends on your environment (how much the plant drinks, how big you pot is, what your humidity is, and so on.
My plants require watering every 3 days. Yours may be different. With experience you will be able to judge soil moisture content by the weight of your pot. Another way to check it is to stick your finger in the dirt (the soil should feel dry.)
Keep in mind that overwatering isn’t how much you water, but how often you water. Soak the soil, let the soil dry out, then soak the soil again. Cannabis withstand dry soil far better that wet soil.
Gotcha, i probably dont ever let it dry out enough then.
These wet/dry cycles are required for good root health. Happy roots = happy plants.
The dry cycle provides the roots the needed oxygen
I was scrolling to say same as others. Full strength jacks is usually plenty of nutrients. Make sure you completely soak pot when you feed instead of giving predetermined amount. Then allow to dry out so roots can get some oxygen before feeding or watering again.
Bigger roots = bigger fruits 
Looks like a nitrogen deficiency to me yellowing from the bottom.
Potassium looks like a banana when it starts going bad.
Whatever part of jacks is nitrogen I’d give some extra once or twice then go back to normal schedule.
Just my opinion.
P.s. pretty sure the yellowing i had goong on was from my soil being too hot. I dont normally check runoff but i will now. Did a good flush on them, reset my levels, and they are looling alot better. I think i may have had some lockout going on too