Problem slowly killing off leaves one plant at a time.. HELP! :)

[Zacarino]

Hi all!

Attaching some photos for quick review, detailed explanation below. I don't THINK this is a nutrient lockout issue but I'd love to be corrected, I'll attach the nute schedule and environment info below also.

Basically, I pulled one plant out because it was a runt and had 1-2 leaves browning and curling upwards/crisping up around the edges per day. Now I'm seeing the same signs on another plant that's been healthy (at least above the hydroton) it's entire life. If it was a nutrient issue I'd think all of them would be showing signs together (only running 2 strains).

Quick rundown -- I'm a legal medical grower in Maine and I've grown a handful of times via coco and DWC, but this is only my second run on my custom RWDC and I can't figure out what the hell is going on.

I run a 24 bucket RDWC system that's all interconnected to one rez (~ 85 gallons with rez and PVC pipes) and uses a single pump. I tapped the buckets from the bottom for the inlets to prevent the roots from growing in against the flow, and tapped about 2/3 the way up the buckets with a 2in wide PVC for the drain.

I left for 2 weeks and had some friends watch things during week 3 of veg. One friend let it get WAY too hot in the room for at least 3 days (95+) which must have also made the water very hot. I had them spray with Heavy 16 Foliar so luckily the temps didnt kill the foliage.

Roots grew into their drain pipes and I had to pull them out by hand after I was home, some several feet and what felt like encompassed the entire diameter. The roots LOOKed a bit darker, but I also use beneficial bacteria powders, one of which is black, so I'm not convinced this is a root rot symptom versus a build up of those because it acted like a filter etc.

Anyways, below are the nutrients I added. The grow room itself runs from 78-83 degrees and the humidity is kinda low, 35-50. 2 fans in the room that make some branches gently rustle and 1200PPM of CO2.

Really concerned whatever is happening will continue to spread to the others systematically. Rez temp is at 72 degrees, chiller came today I'll drop it down to 65 if I have to if anyone thinks this is a result of root rot.

SORRY FOR LONG POST thanks for all mentors

 

[Zacarino]

Nutes added to 80 gallon Rez

Nutes added to 80 gallon Rez

Nutrient Total mL per 80 gallons
Heavy 16 Prime 75
Heavy 16 Fire 75
Heavy 16 Finish 187.5
Heavy 16 Veg A 600
Heavy 16 Veg B 600
Florablend 375
Floralicious Plus 75
Hygrozyme 375
Silica Blast 225
Cal-MAG 150

Resulting PPM 880

 

[Zacarino]

Should have added

Should have added

I use 110L airpump and run a spider airstone to each bucket, so root rot shouldnt be able to live easily at all in the buckets.... I'm wondering if it's possible that if the roots clogged the drain pipe, if that stopped the water flow enough through the drain pipes, that the bucket roots would stay healthy and oxygenated but perhaps the ones that grew into the pipes caused the inlet pipe to basically stop, turning the bucket into a regular DWC but provoking root rot in the pipe? I also understand root rot could theoretically cause any symptom ... ugh

 

[OG Tree Grower]

Last two Picts look like a combo of bleaching and ph lockout, was it close to the light?

Did you rinse the hydroton and stabilize it?
Is the hydroton wet at the base or submerged in water?
Did you Top feed for the first few weeks?

 

[OG Tree Grower]

Last two Picts look like a combo of bleaching and ph lockout, was it close to the light?

Did you rinse the hydroton and stabilize it?
Is the hydroton wet at the base or submerged in water?
Did you Top feed for the first few weeks?

You'll know if you have root rot just look at the roots and feels them, if there brown and mushy you have it , if there firm and just off white or just a brown tint from b-1 or whatever your good

 

[Zacarino]

Several of the leaves were large lower fan leaves although I do run my lights only 12" away -- I don't think it's the light.

There's about 2" between the bottom of net pots and the water. Bubbles keep the root zone moist. I pre-pH'd the hydroton and yes I did top feed for the first 2 weeks.

The pH runs between 5.5 and 6.0 but I also use Heavy 16 Prime which buffers pH if you have it within 5.5 and 6.5 for DWC.

 

[Zacarino]

How long does it realistically take root rot to develop in a system of 72F water temp without aeration? Less than a week? I might just drop the water temperature down to 65 and stunt the plants a little but see if the symptoms stop... that should be too low for the root rot to grow

 

[OG Tree Grower]

Top feed for a week to flush the hydroton, I bet your ph has climbed in the medium and locked you out. I've had it happen before with hydroton

12" away for your light? What are your running for a light?
You said your friend let it hit high temps for a few days, chancea are that's how you burnt the leaves, light bleaching can show up in lower larger fan leaves , I'm not sure why but I've burnt mine before when too mid sized leaves were still good.

IF you have root rot dropping the temp won't help ya, it only slows them down. You need to identify the problem before jumping to drastic measures.

Root rot is easy to pin point and moderately easy to kill or at least limp through the crop. Just do a search on it and tons will come up

 

[Zacarino]

Lights are 1000W MH ice blue bulbs but use the XXXL magnum hoods and cool them greatly, it's really not too hot below them. The plant I pulled out I put by a window and without air for a test and some leaves still browned up over the last couple days so I really don't think it's the light.

I can run some pH'd water through the plant I pulled's hydroton and test the runoff to see if there's a change to test that?

 

[OG Tree Grower]

Dunno, I've never tried to test hydroton runoff. how's the new growth look? Any leaves twisty?

 

[soil margin]

Doesn't look like root rot to me. That usually gets the whole plant drooping. Looks like you got multiple deficiencies. Some kind of cal/mag causing the necrosis and perhaps phosphorous bending the leaves.

 

[Zacarino]

Thanks

Thanks

Dunno, I've never tried to test hydroton runoff. how's the new growth look? Any leaves twisty?

New growth looks a little light yellow, but nothing out of the ordinary... I'll try pHing some water to 5.5 let it settle overnight then flush them all from the top a few times each incase the hydroton is helping cause the lockout

 

[Zacarino]

I think you may be right

I think you may be right

Doesn't look like root rot to me. That usually gets the whole plant drooping. Looks like you got multiple deficiencies. Some kind of cal/mag causing the necrosis and perhaps phosphorous bending the leaves.

I was afriad of it being early signs of root rot helping cause some lockout, but the more I look at it the more I'm thinking it is a bigger Mag issue and a slight Cal one as well.

I just hit the rez with a higher dose of botanicare cal/mag -- I'm using well water which has a decently high level of calcium anyhow. Hoping the calcium levels dont get too high to cause another lockout.

 

[doams]

those spots on leaves looks like ph issue to me.

 

[RoostaPhish]

Looks like phosphorus def. to me. Ph seems a little low for my liking. But I know folks get away with it.
Edit: If it was me, I would set it at 5.9-6 and try to keep it there.