WW XTRM from AMS - First Grow

[adk10000]

Hi everyone!
25 year fan, 1st time grower. As you will see, when I commit to something, I go all in. I want to learn to grow Cup-like stuff.
These are actually 4 plants, 2 strains. (2) WW XTRM from AMS (left side), and (2) of their 'Regular' WW (right side).
I'm in week 6 of flower on these girls and I'm very impressed so far. But the past week, I started seeing what appears to be red rust spots (pics attached). At first, my experienced friend said it was Ca and/or Mg deficiency, so I increased calmag slightly. But after further reading, I'm wondering now if the issue is related to wind burn (fan was pointed at the affected tops, and only tops seem to be impacted), heat stress (only 8-12" from Kind LED K3 – L300 Grow Light), and/or a combo of those and low humidity. Although all 4 RH modules in the small grow space read right about 50%, that dehumidifier is pulling 35-45 pints a day. There is a ton of foliage and you wouldn't know, but I defoliated the ever loving crap out of these plants - the genetics just pump out so much vegetation it's crazy - it's still blocking tons of bud sites and I'm tucking fan leaves every day.
You can see cupping in some of the leaves in some pics -> heat. Whenever I to a res change the water temp jumps from 68 to 74 (room temp), and then slowly drops back down. Would warm roots cause the cupping too or just warm air temp?

Air temp inside the closet never reaches past 78. If I lower the A/C another 2 degrees (Res 66, Air 75), would that help? Or, should I be super-cropping? Or, should I reduce my lighting for the last 3-4 weeks to 11/13 or 10/14? Can I try LSTing the affected tops away from the light?


Some Quick Facts:
This is a closet grow 2x2x4
Good ventilation
Dedicated, portable A/C, Humidifier and Dehumidifier to keep RH & Temp where I want them
DWC
RO Water
pH and temp probes (connected to my fish tank controller so I get real time and log info)
Using Technaflora nutrients - started at 1/4 strength, now I'm at about 70% full (900-1000ppm) in week 6 of Flower.
pH 5.5 - 6.2 (usually high 5's)


If you see anything worth noting in the pics, please share. I'm a noob, asking for criticism. Any advice or help are much appreciated.
Thanks!

[adk10000]

Thanks for the feedback. I just did a res change yesterday. The old water/mix was at 1050ppm when I took it out (I had been topping off with original strength mix), and the new mix going in was 910ppm. It's still cupping a bit today.
Are the red rust spots related? Any idea what's going on there?

Should i flush with ro ph'd water for any period if time, or just remove half the res and dilute by half.

I just put a hobo in last night, so i will be able to post the graphs it generates for rh and temp.

[RosettaStoned]

I wash all my buckets after each change, or really any time I put something in them other than water. As the example I used 1550. Yes whatever target I set it is usually more than 300 less, all depends on the plant and vigor. It is the most noticeable during flower but happens in veg but closer to change days. If I have a solution mixed I just use that and bring it up as high as I can. I could have to add twice in one week also. If I'm lazy and let it go eight days, at that point I need to add water only in most cases. It really doesn't do what you say until around week six when i am at my max ec and from there it stays stable the rest of the way.

[RosettaStoned]

No rinsing, just drain and put in new bucket.
Yes, for the most part it's the "normal" way but during the those 6 first weeks it hard to tell what I'll actually need

[RosettaStoned]

Campesino
My comment below reminds me that I do kinda flush my res when in a net. But that's still not the roots, just to dilute what couldn't be pumped out. Right now it's just bucket changes.

I just did a change the other night and at week six, ec 1670, went down to 1423 the next day but barely any water missing. We'll see what it is tonight

[Canuck147]

Great answer Campesino - Great looking plants adk10000

[adk10000]

Thanks so much. I do keep records, and when I put all the numbers together in a summary, your hypothesis seems like you hit the nail on the head.
Started 12/12 on 6/1/18. I thought that the increased flower was taking the increased nutrients, guess not!
First symptoms were noticed around 7/2.
You think 500 is a good target?
What can I expect to see (or not see) in terms of recovery.
Thanks again!

5/5/2018		275
5/12/2018		355
5/19/2018		303
5/24/2018		580
5/28/2018		395
6/2/2018		493
6/5/2018		500
6/12/2018		887
6/24/2018		998
7/4/2018		933
7/11/2018		919

[adk10000]

PPM tested just now at 1080, following a 919 ppm res change yesterday. I replaced at least half of the volume with RO. ppm says 710, but I think it needs a little more time to mix, and may come down a bit more.

[SovietStoner]

It may be poor AIR CIRCULATION.
How many fans do you have in there? Cause I only see one small USB fan in the picture.

[adk10000]

I have 2 of these little 4" fans:

https://www.amazon.com/gp/product/B00PUSZD2C/ref=oh_aui_search_detailpage?ie=UTF8&psc=1

One above, and one below the canopy. The whole space is 2'x2'

[adk10000]

They have a similar look today. Topped off with just ph'd ro water. They took close to 2 gallons. They also seem to be a bit less sticky today. Is that possible? Does it make sense? Doesn't sound good....

[adk10000]

ppm is 604.
Last total clean out was 6/5, but given current growth, because of the way the DWC and trellis are set up, I can't really take it all apart until after harvest without potentially risking root trauma. I already have a new DWC design that I'm working on...
pH is 5.44. The majority of my research has said to keep hydro ph 5.5 to 6.5. I recently read that 5.2 to 6.2 is ideal. So, I'm not going to make an adjustment from 5.44, but what do you consider the proper range?
Thx

[adk10000]

First day of temp/rh logging. Looks like 65-67 degrees at night, 75-78 during day. Not sure what the RH spikes are. I would guess that maybe when I opened the cabinet, but this is happening at night when the cabinet is most definitely closed. Do the plants transpire more at night? It will be interesting to see the patterns develop. This Hobo is pretty cool.

[adk10000]

Here is the past week of pH and water temp

[adk10000]

pH this morning is now down to 5.3.
FYI, I have been using hydroguard for the entire grow.
As you suggested, I'm going to do my best to deep clean the res and do fresh mix at 50% strength - target 500ppm. Will post back.
Thanks again!

[adk10000]

Did res change again this morning. I was able to get virtually all of the water out, to make a more complete water change than usual. In the past, I didn't tilt the res back to allow the pump to remove the most possible.
Fresh mix is in at 493ppm, and pH is 5.62
Any suggestions on threads for DWC design ideas? I learned a ton already from intergalactic_harvester in the Number 2: Kosher Kush DWC thread.

[RosettaStoned]

After you get almost all of the solution, you could pour fresh water in to further dilute what's left. Then just pump that out. I have to do this when my plants are in a net. 2 cents

[RosettaStoned]

It takes a gallon to dilute 300 ec and I certainly do t leave that in there, maybe a cup...maybe. besides I take numbers after I fill the buckets back up. Still doesnt explain when i just change buckets though. Campesino

[adk10000]

Good tip. I will definitely try that next time. Thx

[adk10000]

So pH began dropping rather quickly, I have topped off with RO & pH Up. You can see in the attached pic, that the pH tends to drop between top offs. I found that when the ppm was higher, that pH tended to be much more stable.Does this indicate if they are taking more nutrients vs water or vice-versa??
ppm is now about 400
I also noted what looks like minor bleaching of a few of the tops that are directly under the lights. Does this indicate that the leaf cupping may actually be heat related?

[adk10000]

Thanks again for the insight.
So I topped off again with some nutes to bring ppm back to 500.
i also ordered the blue labs connect so I can really dial in and track ppm. Should I push it back up to 700 ppm?

[adk10000]

Today is week 7, day 6. Expecting 9 weeks (but what the hell do i know, 1st grow and all). Breeder says 8 weeks for one strain and 9 for the other.

[adk10000]

I'm counting from 12/12, so correct me if I'm wrong ,but I can add at least a week to the breeder's estimate. Correct? Should I go back to 700 through week 8, then drop to 500 in week 9, then flush for (what? 3 days)…??