Stressed plants flourished for a few days, now droopy and dying

[Aaron_Spacemuseum]

Hello everyone, I'm going by "Aaron" and I've finally hit a problem with these plants that I can't figure out from googling.

These plants are all DWC hydro, 5 seeds each of auto-flowering, feminized White Widow and auto-flowering, feminized Blue Dream. All seeds germinated (started 4/20 by pure coincidence), but because growing was a spur of the moment decision coupled with the onset of COVID in March, I was unprepared as far as knowledge and hydro supplies and consequently the plants underwent a great deal of stress! Unfortunately I lost track of which plants were which, but I don't believe that's relevant to my problems.

When they germinated I still hadn't received my expected supplies so I planted them in Miracle-Gro potting soil, my first mistake. They flourished for a bit before getting nutrient burn - I eventually transplanted them into a makeshift DWC setup - and they flourished again before I (think) overdid the nutrients.

has it been repotted? and when?: Seedlings were transplanted from Miracle-Gro to rock wool/rinsed lava rock substrate between weeks 1 and 3 after beginning germination. PH was ~7 prior to week 4.

nutes or additives used: GH trio, ~350ppm from ~110 tap water until roughly week 4, then ~650ppm

Air temps (max min): 70f/70f - does not seem to vary, plants are in the basement

Res temps (max min): consistent 72.5f for several weeks (I assume the LED is heating the reservoir)

humidity: 45%

lighting type and wattage (hps, led, cfl): Mars Hydro LED 600 (600w equivalent LED, 100w)

Light schedule: 18/6 with Mars Hydro 600 LED (roughly 12" from plants at the very closest. As of 6/10, ~3 feet above the plants to hopefully eliminate light burn as a culprit.

ph level: 5.5-5.8 (most recently)

EC (hydro and coco only) - most recently, ~250

Background EC - ~110

feed schedule and nutes (for hydro and coco) - I haven't kept a detailed log but I was unable to PH the water until several weeks into the seedling stage, and my tap water is 7.5 with some variance. The highest ppm my plants have been fed with hydro is ~650, with an even proportion of GH trio nutrients.

Here they are on 6/10:

[Aaron_Spacemuseum]

By comparison, this is 6/2 and 6/5

[Jingo]

You're in trouble the way those roots look, you're getting some biofilm build up which is caused by anaerobic bacteria. If you have a hydro store nearby get something like hydroguard, if not a pharmacy might have food grade hydrogen peroxide but it's got to be about 30% hydrogen peroxide.

If you buy hydrogaurd follow the instructions, If you buy food grade H2O2 then put two mil for one gallon of water next time you do your res change.

Do you have air stones down there in the reservoir? If not you need to get those in there ASAP, if you do you need to try and increase the air flow.

It would also be a good idea to pick up a half a dozen 1 l bottles of water if you have room maybe even a dozen and put them in the freezer. Then you take one out every so often and put them down in your reservoir keep that res for a little bit cooler until you get those roots cleaned up and nice and white.

The option that I like best as far as hydroguard or food grade H2O2 is actually SM90 if you can get it in your area. 2 mil per gallon of that in the reservoir is also great. it's mostly coriander oil and it has some plant stimulants that help plant really pick up.

My 2020 outdoor grow autos and photos in pots

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[Aaron_Spacemuseum]

Thanks! So not just nutrient staining then? I did notice a biofilm (felt it but not visible) on the air lines during the previous two 10-day reservoir cleanings, so I'm thinking that's probably it, even though I don't feel it or smell it this time (yet).

I haven't been able to find either 30% h2o2 or Hydroguard locally so I'm ordering some, but in the meantime... I can get plenty of 3% h2o2, but will that do it? I also have a large compressed oxygen cylinder for my cutting torch...

I should have mentioned, I do have an aquarium air pump running both outlets to the reservoir (well, one in each reservoir as of last night) on full blast with 14" air stones, the water is quite bubbly and the bubbles popping seem to keep the bottom of the lid wet. There's also a water pump that I initially tried to use for drip irrigation but is now just keeping the water in the reservoir moving. I actually worried I might have too many bubbles since they seem to propel the roots upwards so much.

[Jingo]

Very rare to have too much air, remember if you can lower your res temps that reduces your need for oxygen and makes it a lot harder on the anaerobic bacteria.

How are you deciding your feed levels?

My 2020 outdoor grow autos and photos in pots

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[Aaron_Spacemuseum]

What's the safest lowest temp to keep them at? I can keep cycling frozen water bottles in there for months no problem.

For the feeding levels, I've seen it recommended to use half the strength indicated by the GH trio instructions, and half of that... but it's been very difficult to tell exactly how they're responding based on these ongoing problems. After getting nutrient burn (or what I think was nutrient burn) several times I've been giving them as little nutrients as I dare. During the week or so period that they did great, the PPM was at ~250 (tap water is ~110). I increased it gradually to 350 once I thought they were doing good, but then this latest droopiness started.

As of right now, I have all 9 plants in the secondary reservoir with PH'd tap water and 64oz of 3% h2o2 and I'm hoping they'll start to perk up.

When I clean the reservoirs I've been rinsing out the air stones and soaking them in 3% h2o2 in a bucket for a bit, cleaning the air lines with 3% h2o2 on a rag, wiping out the reservoir with h2o2, etc. It's definitely not a lab quality sterile situation but the bacteria is still puzzling to me. One thing I've thought of is that the chlorine in my tap water is mostly gone (as far as I can smell) after 2 days, and my understanding is that a little chlorine doesn't hurt them. Would RV/marine chlorine tablets help?

[Jingo]

I'm not sure about the chlorine and I'd probably avoid that. When you fill your reservoir back up give them 3 mil grow, 2 mil micro, and 1 mil bloom per gallon. They should be able to handle that just fine at this stage I think. Your going to have to check your parts per million and your pH in your reservoir at least once each day and keep track. Then we can adjust the fee based upon this chart.



So you're going to be keeping track of whether your water level is rising or falling whether your ppm/tds are rising or falling and whether your pH is rising and falling.

My 2020 outdoor grow autos and photos in pots

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[Aaron_Spacemuseum]

At this point the plants are a little perkier, some still look bad, but the new growth, while somewhat thin and curly, is standing out horizontally. Water level is falling (just barely, could be evaporation) and I've kept it around 62f. EC is falling slightly, down to an average of maybe 390 from about 420 a few days ago. PH seems to have gone up just barely but it's still really close to 5.8.

There's still no film on the tubing or anything in the reservoir, and the roots still smell like spicy fresh lettuce... I'm not sure if I had a root rot problem in this current reservoir. The one thing I was doing very differently was mixing the GH trio at 1:1:1...hopefully that correction gets them healthy.

Since these are autoflowering plants, are they just going to start trying to grow buds in spite of being so stunted?

[Jingo]

Well with your water level falling and your total dissolved solids falling your pH rising just a little that's against the plants have exactly the right nutrient solution they need at this time. You'll just have to keep monitoring and as long as you're getting similar results they should perk up and look better, after that you can determine whether they're going to flower properly.

Sent from my SM-G955U using Tapatalk

[Aaron_Spacemuseum]

Today I cleaned out the smaller reservoir I've been using the last week, no signs of bacteria or anything foreign, but it had gotten quite a bit of small root material circulating and I'm hoping to head off any infections before my Hydroguard arrives.

I had left the larger reservoir running with an air stone and the aquarium pump for circulation, and it had quite a bit of snotty white stuff in it. Not much of an odor, but there was a lot of slimy buildup on the top of the air stone and on the water pump intake mesh. Whatever it was might have stunted the plants before I transferred them.

They are still struggling along, not a great deal of change...