Grow Mediums autopot coco + gh nutes question (pics)

[VirginGrowbile]

Didn't realize there was an autopot subforum, I originally posted this in the Autoflower Infirmary for Sick Plants - mods feel free to let me know which one to keep

Here goes!

My first grow was hand watered FFOF+Promix soil in 5 gal fabric pots, 4 plants, CKS White Widow photoperiod, 500g-ish dry. Great experience.

This is my second attempt, switched to autopots because I was tired of hand watering and have too many commitments. Did a bunch of research and AFN was one of the most helpful and introduced me to autopots. I'm now growing Iced Grapefruit from FemaleSeeds and Critical Hog from THSeeds - all photoperiod as well.

Everything was perfect up until turning on of the autopots on day 31 (from germ start). Started seeing some deficiencies, mainly on the sativa dominant Iced Grapefruit. The indica dominant critical hog seems to be doing alright I hope. Check out these albums!

ALBUM - Day 48
Iced Grapefruit - Yellow Tag
Iced Grapefruit - Pink Tag
Critical Hog - Green Tag
Critical Hog - Blue Tag

ALBUM - Day 49
Iced Grapefruit - Yellow Tag

Day 50 update: I added epsom salt and it raised the EC to 1950 (a little high perhaps) - Iced Grapefruit yellow tag is starting to show some brown tips.

I'm thinking it might be cal-mag. So I kept cal-mag 5ml/gallon. I lowered cal-mag for 1 reservoir as I changed to tap water only (no more RO to dilute). But upped it again a few days later. I tried to foilar feed cal-mag as well. Could it be that pH swung too much in the beginning when the autpots were turned on?

I'm thinking of using Epsom salt but I've never done that before, would you add it in the reservoir (how many tsp or tbsp/gallon?) or foilar feed? Adding it in the reservoir would affect EC (I'm currently at 1500 EC, pH 5.6 in reservoir).

Details:

• Indoor grow using Autopot 4pot system, with 2 reservoirs (1 reservoir for 2 plants each), two water pumps to keep the reservoir mixed for 15 minutes every 3 hours, 13" fan blowing across the room for 2 hour intervals
• temperature and humidity range of the growing area
  • 22 - 26 degrees celcius, 50 - 62% RH
• growing media (type of soil, coco, promix, hydro, etc)
  • coco/perlite mix 70/30, hydroton at bottom 1.5 inches and top as well
  • air dome at bottom of pot
• is this an organic grow?
  • no
• water source (city, well, RO, distilled, etc)
  • city
• water pre-treatment (filter, chemical, passive offgas, boil, etc)
  • none, straight tap
• water pH before acidification or nutes
  • pH 7.6 tap water after sitting for 2 days
• water total dissolved solids (TDS ppm) before acidification or nutes
  • 320 EC
• nutrients used (brand, amount used per week) - to make a 4 gallon batch (15L) and added in this order
  • GH Armor Si (1 hour wait) - 4ML
  • GH CaliMagic - 20ML
  • GH Micro - 10ML
  • GH Gro - 10ML
  • GH Bloom - 5ML
  • GH Diamond Nectar - 20ML (used it twice in three batches, left it in water overnight and it didn't separate)
  • pH Down - to get to 5.8
  • House & Garden - DripClean - 1.5ML
• nutrient feed solution (pH and ppm or EC)
  • Handwater once/twice a day - from solo cup to autopots before turning on - 1100 EC, pH 6.1 - until Day 31, used RO water with 5ml/gallon to dilute
    • Growth was green, looked really healthy.
  • Day 31 - Autopot turn on, EC at 1220, pH 5.8 (but drifted to around 6.3 in reservoir)
    • Topped to 3rd node (from 6th), and removed growth tips under 3rd node
  • Day 39 - noted some deficiencies on Iced Grapefruit (Yellow and Pink tag). Pink showed lighter green leaves and darker veins. Yellow showed yellowing leaves with some brown spots. This started from the bottom fan leaves.
    • pH in trays were around 5.9-6.4.
    • Between day 31 - 39 - it grew back quite OK after topping bounced back within a few days
  • Day 41 - performed second topping and LST to Iced Grapefruit on first 2 main branches
    • foilar feed cal-mag
    • signs continue to worsen
  • Day 42 - changed reservoir, now upped EC to 1330, but reduced cal-mag to 10ML since I stopped diluting with RO water and just used tap water
  • Day 46 - changed reservoir, now up EC to 1520 and cal-mag upped to 5ml/gallon again. I'm thinking it's deficiencies of some sort
• how are you measuring pH and ppm or EC ?
  • using Apera PH-20 meter, and HM-Digital AP-2 EC meter
• how often are you watering/feeding the plant and how much?
  • from solo cups (once-twice/day) handwater
  • day 31 turned on autopots
• do you get runoff when you water? How much?
  • no runoff in autopots
  • water in trays were ranging from 5-9 to 6.4, and reservoir was 5.8 - 6.2. Some EC in trays were same as reservoir, but some were lower by half.
• do you always have nutes in the water or do you alternate with plain pH'd water?
  • always nutes in reservoir. Should I be swapping this out with regular water?
• what are you using to acidify the water/feed?
  • pH down concentrate
• what is the runoff pH and ppm or EC?
  • no runoff
• type of light used and wattage
  • 2 x 250W QB 3500k V2 RSpec - LM301B Samsung LEDs, 2 strips of 660nm red leds in middle (I know this is perfect for a 4x4)
• size of tent AND size of room where the tent is
  • 5x5 tent - in basement about 1k sq feet
  • dehumidifier - switched on if lights out humidity goes past 60%
• ventilation details (quantity and types of fans and filters)
  • 13" oscillating fan every 2 hours
  • 6" exhaust system (AC infinity)
• details about former or current pest problems and treatments
  • no pests from last soil grow
• unusual details that you feel might be relevant like: my cat shit in the soil, etc
  • none

Thanks in advance

Iced Grapefruit - Yellow Tag - Day 48

Iced Grapefruit - Yellow Tag - Day 49

Iced Grapefruit - Pink Tag - Day 48

Critical Hog - Green Tag - Day 48

Critical Hog - Blue Tag - Day 48

 

[GolfnRL]

Hi VirginGrowBile. I had a similar experience with the autopots in my first grow. My plants had similar leaf symptoms but I treated mine as a nitrogen deficiency. That seemed to be what was needed. Also, that grow was super soil, but because I saw the leaf issues I began watering/feeding with nutes in the rez. The plants perked right up. I added Epsom Salts as well on a diluted basis the rest of the grow.

 

[VirginGrowbile]

Hi VirginGrowBile. I had a similar experience with the autopots in my first grow. My plants had similar leaf symptoms but I treated mine as a nitrogen deficiency. That seemed to be what was needed. Also, that grow was super soil, but because I saw the leaf issues I began watering/feeding with nutes in the rez. The plants perked right up. I added Epsom Salts as well on a diluted basis the rest of the grow.

hey GolfnRL! thanks for the advice. How much Epsom salt do you add per gallon or litre? and what do you aim for EC wise? Do you count the EC of the starting water in as well? I start with ~300 EC tap water (~150ppm).

cheers mate!

 

[GolfnRL]

I added the Epsom Salts at 1tsp per gallon initially. Then at the rate of 1tsp per 4 gallons of water. I counted the total PPM and the target was 800 or below. I treated the affected plants by sucking out the water in each pot's reservoir with a turkey baster, then replacing that water (about 12 oz) with the nutes solution I thought was necessary to treat the problems, and finally, switched out the water in the rez. I focused more on the PH than the EC/PPM. Throughout out the grow the PH in the rez was 5.9. and when I checked PPM it was usually right around 800.

 

[St. Tom]

I added the Epsom Salts at 1tsp per gallon initially. Then at the rate of 1tsp per 4 gallons of water. I counted the total PPM and the target was 800 or below. I treated the affected plants by sucking out the water in each pot's reservoir with a turkey baster, then replacing that water (about 12 oz) with the nutes solution I thought was necessary to treat the problems, and finally, switched out the water in the rez. I focused more on the PH than the EC/PPM. Throughout out the grow the PH in the rez was 5.9. and when I checked PPM it was usually right around 800.

that's a superb idea with the turkey baster as if I've had bad issues i would start top feeding them as I've grown with autopots fora a good few years now and when sharing a res with multiple strains it can be tough to keep everyone happy