autopot coco/perlite, nute deficiency or lockout?

[VirginGrowbile]

Hey guys! Happy to finally join AFN and get in on the action.

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!

• 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
  • 0.32 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 - 1.1 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 1.22, 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 1.33, 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 1.52 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

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 1.5 EC, pH 5.6 in reservoir).

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

 

[namvet25]

Some look like they could use some nitrogen.and some look fine.I'm not a hydro man but make sure your ph and ppm are correct.

 

[St. Tom]

as nammy said ph is very important with autopots but you seem on top of that and as i grow in coco i can't help you but i know a fair few who grow in soil i will tag someone for you @pop22 as that's the person i would ask

 

[Simplicio]

I severely nute burned 2 plants in autopots with 600 ppm (EC=1.2) using Growpito medium. I don't think the medium had an effect.
If I read correctly you're above ppm = 1200 (EC=2.4). That probably would've killed my plants.
I'm using EC=0.8 right now (ppm=400) at 2.5 weeks.

Your problems might be over-feeding.

 

[Mizzo81]

as nammy said ph is very important with autopots but you seem on top of that and as i grow in coco i can't help you but i know a fair few who grow in soil i will tag someone for you @pop22 as that's the person i would ask

He’s in coco not soil. Maybe u could be more help lol.

 

[pop22]

looks like nutrient lock out. Are you using that tap water for your solution? It could well be that, I'd stick with RO or at least blend it, that's some HARD water at 320 ppms! Also, get rid of that pump in the res, it's not needed and stirring the res like that ups the PH. Is your EC including the 320 ppm of the tap water? As to cal mag, I use 10ml per gallon and have never had an issue. 9 times out of 10, its a mag issue, and just as often that is caused by a PH issue.
Also are you running those Sativas on the same res with the Indicas? That can have very different needs and reactions to nutrient solutions.

This plant is growing on an EC of 1.1 ( 550 ppms ) PH 6.4. Feed started on day 10 and stays the same start to finish. My solution is made with RO only!

 

[pop22]

Also, do you ph your solution then let it ist for 24 hrs? solution will almost always rise in PH during that period. I let the solution sit ofr 4-8 hours, then adjust to 0.2 less than my goal and wait another 16 hours or longer, check and adjust again. . do this before you ad it to the res.

No my plant is not in an auto pots but it is being bottom fed. I've run auto pots for 4 years and still use them often.

 

[VirginGrowbile]

awesome, love the responses. btw, I go by EC in ms/cm, not PPM. I'm pretty damn long winded so I'll try to answer them all here

Some look like they could use some nitrogen.and some look fine.I'm not a hydro man but make sure your ph and ppm are correct.

I've been adding General Hydroponics MICRO at 2.5ml/gallon, and I usually mix a 15L (4 gal) batch, so 10ml/4gal batch. Would upping to 15ml for my next 4gal batch be too much? Some say it's calcium and magnesium because I'm running quantum board LEDs. pH has been around 5.8 in reservoir. I added 3 tbsp (9 tsp) of epsom salt to my ~25L reservoir 2 days ago and it brought my EC from 1.55 to 2.6!! I had to add in RO water to dilute down to 1.95 EC (just under 1000ppm). I feel like every time I prepare my nute batch, I have to dilute it and it could cause nitrogen def.

as nammy said ph is very important with autopots but you seem on top of that and as i grow in coco i can't help you but i know a fair few who grow in soil i will tag someone for you @pop22 as that's the person i would ask

I grow in coco/perlite 70/30 mix this time around, I love the feel of this medium as I came from soil from my last (and first) grow. Thanks for tagging

I severely nute burned 2 plants in autopots with 600 ppm (EC=1.2) using Growpito medium. I don't think the medium had an effect.
If I read correctly you're above ppm = 1200 (EC=2.4). That probably would've killed my plants.
I'm using EC=0.8 right now (ppm=400) at 2.5 weeks.

Your problems might be over-feeding.

yikes I would like to avoid nute burn as flushing isn't exactly good for autopots! the values I reported were in EC (ms/cm). I started hand watering at 0.7 EC, then 0.85, then 1.0, then 1.1, then when i turned on Autopots it was 1.2 EC (600 PPM) in the reservoir. However, I started seeing deficiencies so I upped EC from 1.2 to 1.35, then to 1.55. Then 2 days ago, I was feeling desperate looking at them turn yellow and get worse.. I added epsom salt and brought the EC to 1.95 (about 950PPM). Now you got me thinking... could I have overfed with 1.2 EC (600 ppm)? I thought 600ppm was quite safe, I only upped it because it started to show signs of deficiencies.

looks like nutrient lock out. Are you using that tap water for your solution? It could well be that, I'd stick with RO or at least blend it, that's some HARD water at 320 ppms! Also, get rid of that pump in the res, it's not needed and stirring the res like that ups the PH. Is your EC including the 320 ppm of the tap water? As to cal mag, I use 10ml per gallon and have never had an issue. 9 times out of 10, its a mag issue, and just as often that is caused by a PH issue.
Also are you running those Sativas on the same res with the Indicas? That can have very different needs and reactions to nutrient solutions.

This plant is growing on an EC of 1.1 ( 550 ppms ) PH 6.4. Feed started on day 10 and stays the same start to finish. My solution is made with RO only!

View attachment 1213429

wow buddy LOOKIN GREAT, I wish I could have those nice green colours your plants are displaying.. what kind of lights are you using?

I used to blend my tap water with RO, but I thought to use tap water as it contained some added minerals the plant could use.

nutrient lockout could be a possibility - should I flush? I started off with EC 1.2 (600ppm) and 150ppms were from the tap water. I also topped it quite abit... i'm a little afraid to perform my final 3rd topping to create 8 main colas after the first node of the 4 main lines. I want them to be healthier before I chop their heads off again!

I am indeed using tap water, but I live in a pretty good area where tap water is very drinkable, it's actually 0.32 EC (~150PPM). Is that considered hard? I thought 150ppm is acceptable. The pump is just to circulate and I made sure it's weak so it doesn't create air bubbles. Should I just remove it?

My EC of 1.95 (~950ppm) currently is including the tap water's EC of 0.32 (150ppm). When I first turned on the autopots, I was at 1.2 EC (600ppm) and it did include the EC of the tap water (150ppm) - does that effectively mean I'm only feeding at 450ppms (0.9 EC)?

10ml/gallon, wow ok, i've only been going at 5ml/gallon. One time I reduced it to 2.5ml/gallon as i thought i was overfeeding. The conditions got worse, so I upped it soon after back to 5ml/gallon. I'm mixing up a bunch of nutes tonight to replace my current reservoir of 1.95 EC (950ppm), I think I should go back down to 1.2 EC ms/cm not including the 0.32 EC i started with? Pretty much bring my EC to 1.5 ms/cm considering that my tap water EC is 0.32. I also heard that quantum boards make plants extra hungry for calcium and magnesium.

the sativa hybrid are on a separate reservoir than the indica hybrid, I macgyvered homedepot 45L tote to make a new res. currently, the feed in both reservoir are the same, but it's looking like I have to keep EC/PPM higher on the sativa hybrids.

Also, do you ph your solution then let it sit for 24 hrs? solution will almost always rise in PH during that period. I let the solution sit ofr 4-8 hours, then adjust to 0.2 less than my goal and wait another 16 hours or longer, check and adjust again. . do this before you ad it to the res.

No my plant is not in an auto pots but it is being bottom fed. I've run auto pots for 4 years and still use them often.

I let tap water sit for 2 days or so, then I add general hydroponics armour SI (wait for an hour to dissolve), then cal-mag @ 5ml/gal and the GH trio, etc. I then pH down and add drip clean. It usually stays quite stable after an additional 2 days or so. when i mix new reservoir tonight i'll pH down to 5.6

 

[VirginGrowbile]

Minor update: On day 51, upped GH Micro for Nitrogen (upped from 2.5ml/gallon to 3.2ml/gallon - about 30% increase), and also upped GH Calimagic from 5ml to 7.5ml/gallon. EC is about 1.6-1.65 final (started with 0.32 EC as base tap water).

I noticed that most of the leaves for the sativa dominant plant are now clawing down (maybe too much nitrogen?) Some older leaves are showing some rust spots and still some light yellowing in between veins and stems are red. Leaf tips are also slightly brown.

Two possibilities I'm thinking:

1) May be light burn as some leaves under shade were greener than others, so I moved the lights higher a couple inches (it's currently only running 175W each on a 2 x 250W QB).

2) May be a nute burn due to leaf tips brown, but my leaves are light yellow and were never super dark green... so I'm thinking it could be due to light burn instead?

Iced Grapefruit Pink Tag - Day 55

 

[Mañ'O'Green]

A couple of things I noticed. First your EC numbers are missing the decimal point and that can be confusing to many. Here is a conversion chart so we are all on the same PPM

Like Pop noted your starting water PPM is too high. GH has a hard water FloraMicro nutrient that might work better for you. One reason PH goes up in circulating nutrients is due to the calcium carbonate precipitating out of solution. To mitigate that aerate your water for a day or two prior to using it. That will help to stabilize the PH.

I also agree that you are over-feeding and it may be the source of the lockouts.

I don't understand where this idea of light burn has come from. Everybody thinks they have light burn. If your buds are not up IN the light it ain't light burn. I have run COBs that are much much stronger than scattered LM301s as close as 8 inches without any light burn. If you were talking HID then you can be talking light burn.