Hi guys, my ph question is about the soil. I check the ph on the nute water when I feed the plants. It’s always around 6 to 6.3. My white widow is just starting its 4th week today and the buds are pretty small and I noticed that some of the stems are slightly purple in color. I read online that this might be a case of nitrogen deficiency. I am using Dennis’s and Roberts nutrients but will say maybe going a little light on them as I only have 3 plants and it’s hard to get the measurements right on and I don’t want to overdo it causing burn. The other two are og kush and are about two weeks behind and have some purpling as well. But otherwise seem very healthy. I’ll post a couple of pics. Any help would be appreciated. Thanks 
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A pH of 6.0 - 6.3 should be fine for soil, I like 6.2 - 6.5 for soil better. However the pH of the soil at the root zone is what is most important and a true reading of what is going on with your plant’s uptake of nutrients. You should be testing the pH of the extra run-off from the holes in the bottom of the container. Testing the water after it comes out of the soil there will be much closer to the actual pH at the roots.
Purple can be a sign of many different nutrient deficiencies, including nitrogen, but with dark green leaves as dark green as yours I’m very sure you have plenty of nitrogen and also yellowing leaves without any burning or browning is more pointing towards nitrogen being deficient.
Purpling in the stems and leaf stalks usually makes me think magnesium deficiency, maybe calcium, those would be my first two assumptions and this is usually caused in most cases by over watering.
Over watering can even cause a sort of leaf drooping that is different than leaf wilting/drooping from too little water. The look of your leaves kind of look like over watering, kind of swollen and bloated and also drooping a little.
Make sure you are getting used to the feel of your container totally saturated with water as opposed to almost totally dried out. And wait until it feels very light and almost totally dried out before watering.
Thanks MacG. I forgot to ask that if the soil does have a low ph can I just up the ph to around 7 or would that be a bad idea? If yes, what would you recommend to raise it? I know this isn’t a great picture of the ph but I did use my ph meter and put it about an inch or two into the soil on all 3 pots and two showed 4.9 and one was 4.7. Not a great measure I know but I just wanted an idea. Thanks for your help.
You are not having a PH problem. Ph does not make leaves droop. Ever, and under watering does that. If you had a PH issue; Your leaves would be twisted.
If your pH is really below 5.0, you should bring it up closer to 6.5 for soil, 5.8 for hydro, and in soil you can do this with garden lime or a commercial “pH up” from general hydroponics or something similar, garden lime can be found at most garden supply outlets.
Thanks MacG. At any Garden Store or Dept. in Big Box stores. You can pulverized dolomitic lime. 2.99 a 40lb. bag. Use as MacG directed. Maybe read the bag.
Hey MacG thanks again for your help. I wanted to check the ph from the runoff befor I got back to you. The ph was 4.9 on all 3 so I ordered some lime online as there is none to be found in my town til next year. Everyone I called was out. When it does show up, how would I apply it? Do I just sprinkle it on the soil? I suppose there will be instructions on the packaging. Anyway thanks again and I will post a pic of the girls to see what you think later. Have a happy thanksgiving everybody!!
I found this article that explains quite a bit about garden lime. Most fine powdered garden lime will be sprinkled on the top of the soil and then you would water the plant which would bring the lime down into the soil and to the roots to interact and bring down the pH. Of course, do read and follow the recommendations on the package.
http://www.howtogardenadvice.com/soil_prep/lime_for_the_garden.html