Need help to save my girls!

[MercDod]

Soil Growers:
1. Are you growing from seed or clones? Large 20 gal plant is from seed and the small pot is a clone of the 20 gallon pot.
2. How old are your plants? 67 days old from seed.
3. How tall are your plants? about 12 inches
4. What size containers are they planted in? 20 gallon, 3/4 gallon
5. What is your soil mix? 40% Ocean Forest and 60% Strawberry Fields then added an additional 2 gallons of perlite to this mix. Added some worm castings a few days ago.
6. How often do you water and what type of water do you use? About every 3-4 days on 20 gal and every 2-3 days on 3/4 gallon.
7. What is the pH of your water? 6.5-6.6
8. What kind of fertilizer do you use and what is its NPK ratio? No fertilizer on 20 gallon, 4-35-26 Cultvation Nation, and botanicare cal mag at lowest strength.
9. Do you foliar feed or spray your plants with anything? No
10. What kind of lights do you use and how many watts combined? (HPS, MH, fluorescent, halogen, incandescent "plant lights") TS 3000 at about 350 true watts, 20 inches.
11. How close are your lights to the plants? 20 inches.
12. What size is your grow space in square feet? 16, I'm using a 4x4x80 grow tent.
13. What is the temperature and humidity in your grow space? 79F at about 56rh
14. What is the pH of the soil? Never checked it.
15. Have you noticed any insect activity in your grow space? I did have fungus nats but all are gone with use of mosquitoe bits and yellow stickys.
16. How much experience do you have growing? Had one good grow with coco and flora treo, this is my second grow and using soil this time.

Can you guys help me save my plants? Is this one thing or more? (First 6 photos are the 20 gallon plant.)

 

[GanjaFarmer24]

Magnesium deficiency, use unscented Epsom salts 1 Tbsp. per gallon of water, or just sprinkle it on top of your medium. Unsulfured molasses also has some and its good for the soil too. Try adjusting your water's PH to 5.9-6.0 for better uptake, a tablespoon of lemon juice helps me get it in range, smells nice too.

 

[MercDod]

I used Botanicare cal-mag regularly for watering to try and correct 5ml/G. The plants now look like the photos. Could this be a nitrogen deficiency?

 

[SmokinJo421]

I used Botanicare cal-mag regularly for watering to try and correct 5ml/G. The plants now look like the photos. Could this be a nitrogen deficiency?

Any reason your not using any Bloom fertilizer?
You'll notice majority of them do have small amounts of nitrogen so you won't become deficient. Better to feed as preventative then it is to diagnose and fix.
I've always followed "feeding schedules" for wich ever company I was using at the time.
I'm trying to get away from using nutes in plastic bottles as they can be expensive, and create more plastic waste.
Unfortunately I was not able to build a complete super soil wich means I will be following a schedule this season.
I will be using "Humboldt County's Own "
Complete line and their schedule starting actual schedule beginning of the 3rd week of July then introducing "Bloom fuel" for an easier and faster transition