HELP! RDWC hydro leaves drooping, lower leaves turned brown, curled/dying

[gfass]

5ft x 2.5ft x 6.5ft (height) tent. I bought the HDX totes from home depot. They are black with yellow tops. I've got the 38 gal inside the tent as it fits the tent great (1ft or so on each side, about 8 inches between the front and back. I have a larger 55 gal HDX tote on the outside. I've run 1 1/4 PVC from the inside tote to the outside tote. I've got a 550 gph inline pump and a 32W air pump powering 4 2x4" cylinder air stones. There's a ton of circulation and air in the totes at all times.

For lighting, I have a Mars Hydro 2000W LED. The system is about 65 gallons when filled. I shoot for about 1" below the bottom of the 6" diameter baskets which hold hydroton only for the roots. I used rapid-rooters and have quality seeds from Humboldt Seed Co (Purple Panty Dropper for this grow).

I've taken a full grow journal, updating every day since the start so I can reference back to it for any detailed questions there might be. I've also got pictures at different stages. I can also provide a timelapse video from start to today. showing the progression of the issue. I'm usually pretty good at figuring these things out, but I've got some concerns and wanted to get another set of opinions.

Grow started: 03/22, rapid-rooters in hydro on 03/24
Initial ppm: 200ppm (tap is about 35 for me). Switched to 400ppm on 04/04, and 600ppm on 04/10 (thinking there was a deficiency in phosphorus and/or calcium and/or nitrogen). In my coco setup, I had to use cal-mag to help with calcium deficiencies so I expected this to some extent.
Res temp: Between 64-68.5 typically, night/day.
Dose/nutes: GH (Gro/micro/bloom) @ 1/4 tsp strength (1/3c for my system @ about 250L or 65G). Added cal-mag (2/3c 04/04 and 04/09 for a total of 1 1/3). ph Down to get it in the 5.5-6.5 range
pH: Initially unstable, but got it to stabilize and it spent many days around 5.8/5.9. Actually realized my large totes might be a big problem as the pH drift isn't enough, even with 4 air stones and a 32W air pump, to raise the pH fast enough over time. I tried to bring this up to 6.2+ to help with calcium intake on 04/10.
Tank changes: 1st fill - 03/19, 2nd fill 03/27 (smelled bad - I did UC roots + hydroguard and figured it was a mass kill of the hydroguard bacteria and so I flushed/refilled). 3rd fill, 04/10 - found there was algae or some sort of slimy growth on my black tubes I was using for the top feed tubes for the early stages of growth. I ripped it all out and completely cleaned the tanks to get a fresh start.

My plants' first true leaves started getting curly pretty early on. I thought it might have been too high of heat (got to about 80 degrees F due to the lights heat and reflection of the aluminum tape of the top of the tote and back onto the plants. I moved the lights further way and adjusted to different light % throughout growth, eventually getting to about 75% power, where it's at now. It's about 18" away, which should have a ppfd that isn't too high - probably around 500-700.

Initially, I didn't put any aluminum tape on the totes but I quickly realized that was a bad idea. After refilling the tank on 04/10 and completely cleaning/flushing it, I added better tape to ensure NO leakage on the inside tote or the outside tote. FYI - my tubes for the pump are flexible/clear but I spray painted them heavily with black to ensure no light leakage. There's no place that should be leaking light other than whatever ambient radiation makes it in. But that should be very very little.

When I refilled on 04/10, I did 1/3c (1/4 tsp/g) micro, 1/3c (1/4 tsp/g) bloom, 2/3c (1/2 tsp/g) grow, 1/3c + 2 tbsp hydroguard (1/4 tsp/g), 2/3c cal-mag (1/2 tsp/g). ppm is at 345. pH is around 6.2. Temps are back up (from 49 at fill) to 60. They'll hit 68 again today I'm sure.

I think that I had a nutrient uptake issue because the algae/solids forming in the tank caused the roots to no longer be able to take in the nutrients. I think heat played maybe a minor role early on, maybeeee, but I've kept it near 75 since and it drops to 68 at night. I think the tank got algae/solids due to 2 issues: The older pump I used for the top-feed tubes was probably not totally clean. It might have caused some bad bacteria blooms. The light getting in, even if a little (earlier, when I had covered maybe 95% of the area, but left some uncovered by aluminum tape) probably allowed the growth to go on even more. And since I only have hydroguard, I guess there's no system in place to kill bad bacteria.


What do you guys think is going on with my leaves here?

[gfass]

TLDR: What's wrong with my plants?

[BassBuds]

Your roots look good to me. What are you using to measure your ph? Don't use the cheap amazon pens. They are horribly inaccurate (caused issues with my first grow). Invest in either ph perfect nutrients you don't need to adjust, or a bluelab ph pen. PPM also seems a bit high with a plant this young (especially if you just ripped out the roots).

Clean reservoir with h2o2 and ph'ed water for 24 hours. Then go with half strength nutes and hydroguard (great white is pretty awesome also) for ~ 1 week. I had similar issues early on in my grow, but this technique helped my plants recover quickly.
https://forum.growweedeasy.com/forum...phytomax-2-800.

You won't see your old damaged leaves get any healthier, but new growth should be good

[gfass]

Half strength? I'm using General Hydroponics and Cal-Mag + hydroguard. The GH stuff I've got at 1/2 tsp/Gal strength (2.5 ml/Gal). You think that's too high? I'm just wanting to be sure you meant that as these plants are about 20 days from when they were put in the hydro as seedlings with just cotyledons in the rapid-rooters.

I just flushed 2 days ago and @ 65 gallons, I'm not excited to dump out what I have. I guess I could reduce it down and add water to bring the overall solution strength down quite a bit.

[RagWeedDWC]

Your roots look great, and your correct if you have algae you have a light leak. I use those exact same totes, only way I have been able to completely seal them is to paint them with a plastic paint (I use rust-oleum black) top and bottom of the lid and out side of the container.

Did you top feed these when you started them? I see salts on your hydro media, it could be getting a dose of something in the upper roots.

I agree with backing off just a bit on nutrients. I also use a lot more bubbles than what I see in your photo.

How much separation between the bottom of the grow cup and nutrients, once I have roots as long as yours I try to keep a minimum of a inch and a half. They look a little like they are drowning and that could be the issue.

[gfass]

Thanks for the information! I did use a top feed initially while they were younger. I did that for about 10 days or so. I've now put 2 layers of thick aluminum tape on the top, completely covering every possible location. That being said, there's probably still light radiation getting through, but I don't have the stomach to stop everything and paint these down right now, so it'll have to wait. I'm hoping the second layer I just added will help there.

I'll flush the top out with pH'ed water and get rid of those salts in case that's causing any issues.

I also backed off the nutes today as suggested by you both. I went from nearly 450ppm down to 300 ppm. I replaced probably 40% of the water with fresh 6.6 ph, 35ppm tap water. I then added 1 tbsp of ph Down to get it from 6.5 down to about 6.2.

I turned the bubbles off in the picture to get a better shot. I have a 32W air pump with an 8 way manifold, 4 tubes going into the tote with 4 2x4" cylinder air stones. There's TONS of bubbles going 24/7 so I can't imagine oxygen being too low.

I thought I'd have hydro on lock down after 2 successful first grows. I did soil first, then moved to fabric pots and coco with feed to drain system + nebula manifold training, now this is my 3rd grow and I went with a RDWC and top feed for early stages + SCROG

So is the general consensus that the algae locked out my nutes? If so, how long does it take for them to start drinking properly again? it's been 2 days since I flushed and I was hoping to see better progress to show I've fixed it, especially since I expect hydro to clear up (or get bad) rather quickly. I figured 8-24 hours you'd see big differences with RDWC.

It doesn't appear to be getting any worse, I just thought I'd see an explosion of growth sooner rather than later.

Also, RagWeedDWC, you said you have the same totes - did you really go with the 38G inside and 55G outside or some other combination?? I'm really curious because I'm having SERIOUS regrets about going with a 65-70G system. Seems like there's not going to be enough pH drift naturally from the oxygenation to allow the plant to feed from the entire 5.5 - 6.5 range in a quick enough time to not cause problems. And on top of that, there's all the massive nutrient waste as there's no way the plants are going to be drinking enough, at least not right now. Perhaps it will pay off more in the flower/stretch phase? It seems like it may be a better idea to get a smaller reservoir in order to bring the total system down to say, 30G or so, thus halving my nutrients I lose during a flush and allowing more pH drift.

I originally thought that going with the larger system would mean less maintenance and less frequent flushes. Maybe I screwed up there in those assumptions.

[gfass]

The first 5 leaf pair has some burns showing up on the leaf now too. Although I guess that could be from the higher nutes I just lowered down today. I turned lights from 75% down to 40% to see if it is just too much light right now.

[RagWeedDWC]

I travel a lot so PH has always been a problem for me. I went tot he larger totes to try to help stabilize, but it is still an issue. I use RO water, and a auto top off system. I change nutrients about every 7 days, but I have never fed at the recommended amounts, usually never get above 80% and the end. I mix my top off res at 50% of what I used on the main totes. When I have both plants in flower they will drink almost all of it, I have a line connected to the resivor that feeds pure R/O water and a mix of calmag and hydroguard only by siphon into the top off res. Hard to explain, but basically slowly reducing the mix as it consumed.
Not sure of my tote size, added some pictures for reference.

[gfass]

That makes sense. The totes you have look like the 17 gallon totes. Do you know the total gallons your system is when full?

I'll keep the nutes backed off and keep a close eye on these over the next few days. I guess I could go lower than 300ppm if it might help.

[RagWeedDWC]

Not when completely full, but the grow totes I mix for 8 gals, the top off keeps it at that level. My topoff tote is about 25 gals (I have to be concerned for floor weight), the R/O tub is approx 6 gals.

[RagWeedDWC]

This will give you a better ideal about the totes, but again I grow hydro, so the mixtures etc may be different.
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[gfass]

Well - I'm still fighting this issue. There's a part of me that just wants to push through these issues at this point, regardless, as I want to know what was really the cause and be setup for success if I try again.

I stopped using hydroguard - I want to go with only chemical based nutrients - no more more organics. I want a sterile environment so I can eliminate odd bacteria on bacteria growth issues. That's an environment I know how to maintain better, from my pool experience.

I'm adding 1.2 ml per 60G for about 0.50 ppm free chlorine. So far that's kept the system clean and I've had no new growth issues.

I also feel like I am now pretty certain that the nutrient deficiency I was having was a K (potassium) deficiency. It matches all the online literature and pictures on the issue. I recently added 6 tbsp of Gro to compensate for the lack of K I believe I am seeing. It should be noted that, up until this point when I added the 6 tbsp of Gro to compensate for the presumed lack of K, the lower leaves, WITHOUT FAIL, were consistently going from OK, to burnt tips/edge, to the whole leaf being pretty bad and me clipping them. That's why there's only 1 set of 5 leaf sets on them at this point. However, after adding the 6 tbsp, it APPEARS as though the consistent lower leaf die off has stopped. I know because it was in progress on the next set of leaves, and it stopped. It hasn't seemed to get any worse. I was at 230ppm after adding the 6 tbsp of Gro, so I'm still sitting around seedling strength (1/4 tsp) nute levels.

I then kept a close eye on PPM and water level to see where they move. Unfortunately, the water uptake from the plants is just SOO low right now, due to the fact that they really only have 1 proper set of leaves to draw power from - a single 5 leaf set. The rest have been trimmed off as each set went bad over time from the nutrient issues it was having. I realize this may be a lost cause, but as long as there's life, it's not. The plants have new sets of leaves growing out, and even though I topped the 5th set for a SCROG setup, they are both still growing, albeit slowly.

I would think that, if the plant starts to properly grow again, I'll see the water level and ppm drop more or less together. But that's not really happened yet (water stays pretty much the same when we're talking 60G for 2 very small plants).

Throughout this process, the roots have at times had some brownish stuff on them. I thought it could be clay residual. Or root rot I guess, but each time I had any buildup I caught it and drained it immediately. I've also sprayed 3% H2O2 on the roots (today) to be really sure any bad stuff on the roots is dead. Early on, I noticed laterals growing, but lately, the roots are growing vertically albeit semi-slowly, but they don't have a lot of lateral roots coming out yet. All of this just means that it's growing very slow. I'm hoping that at some point, the roots start to do their job and the whole plant picks up. I guess I'll know more in a week.