XJ-13 (Jack Herer x G-13) problems

Hiya-

So this is my first post here, though I've been reading the forum for a little while. I've got some growing experience, but never with XJ-13- and I'm having some trouble (see pics).

Some of the leaves have been curling (around the edges) upward since very early in the vegetative cycle. I've never seen this before, but maybe it has to do with the strain?

My main concern is with the brown spots and dead leaves I'm finding. I have been pruning them off every week or so, but they do keep returning. I am thinking I should try lowering the PPM (maybe this strain is very susceptible to nutrient burn?). Does anyone have some ideas as to what might be causing this type of damage?

Let me describe the setup:

• 6x 600-watt HPS
• DWC (deep water culture) in 20gal reservoirs, 9 plants each
• 2x one foot air stones and pumps in each res
• "Stadium" SCROG technique (where plants are woven into a U-shaped trellis)
• Filtered air intake and carbon scrubbed exhaust: maintains air temp around 78-degrees and 50% RH
• I've been keeping the plants at the recommended GH (General Hydroponics) 3-part nutrient solution table for vegetative growth, around 1,000 PPM
• Maintaining PH around 5.5
• I found some powdery mildew on one of the plants a few weeks back and treated with Serenade (bacillus subtilis) spray. It has not come back, I think it was brought in on one of the clones to begin with.

I'd like to start a grow journal in the future to post my results. I'll keep y'all updated.

mine is doin the same thing what is it

i know for sure that your water is to warm

I never believe those dam tables. I always start out my plants at about 1/4 strength of suggested, and real slowly raise it a little at a time until I just start to get a small amount of tip burn. Then I back off this amount by 10-15%. I have had strains that can chug down 1,800 PPM easily, and others that can hardly handle 500 PPM. So how the hell do these corperations know how much we should use. Same thing when someone in here tells someone how many PPM's to feed at. To me it is worthless information unless this person grew my strain, with the same nutrients and in the same type system.

Now for your plants. Are you sure you have not got some contaminates into your rez? Or that some part of your system might be having a bad reaction with your nutrients. Like plastics or rubbers deteriating. How are you telling what you PH is? Are you useing drops or strips?
I would carefully inspect my system. Clean it real well. Mix up a new batch of nutrients at about 40% strength and double check that the PH is correct. This means if you have calibration solution for a PH Pen that you should get new solution. This stuff can get contaminated or it can degrade. I have seen people that take the solution and pour it into a shot glass, then they will stick their pen in it, and then pour the shot glass back into their bottle of solution. Then stick it up in the window in the direct sun light. One guy was useing the same solution that was 2.5 years old.
What do your roots look and smell like? Do you run some kind of Zyme product? Like HydroZyme or CannaZyme?

thatguy1122 said:

i know for sure that your water is to warm

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Temp is very important in DWC. 65f-68f. Anymore and there will not be enough oxygen in the water. This is why Salmon can grow so much larger in the Cold waters of Alaska. More then Wash, Ore and California.

Lord Dangly Bits said:

Temp is very important in DWC. 65f-68f. Anymore and there will not be enough oxygen in the water.

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Well, would the fact that I have two airstones per res help? Each is attached to a separate pump (no splitters).

Of course, I'd love to lower the temp in the room overall. The daily temp fluctuates between 70-78 on average. I already have a 400 CFM intake and a 1,000 CFM exhaust fan. An AC would be costly to run due to power, and I'd have to run another circuit into the room (already maxed out)... so I'm trying to avoid it.

Of course, if it is the difference between unhealthy plants and healthy ones, I will install an A/C. But, if there's something I can tweak to get away without it, I'd love to try. CO2 should help the plants cope with the higher temps as well, which I'm planning on adding.

What thoughts do you have on how I should proceed? Is there any way for me to lower the water temp without incurring another 1,000 watts of A/C?

Thanks for your quick reply!

Lord Dangly Bits said:

Now for your plants. Are you sure you have not got some contaminates into your rez? Or that some part of your system might be having a bad reaction with your nutrients. Like plastics or rubbers deteriating.

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I've never heard about being very selective about plastics. I'm using large polypropylene containers, those 20gal round tubs with rope handles that you'd put a keg into. Are there specific materials I need to watch out for?

Lord Dangly Bits said:

How are you telling what you PH is? Are you useing drops or strips?

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I'm using a digital PH/PPM meter. I calibrate it monthly using fresh new calibration fluids.

Lord Dangly Bits said:

What do your roots look and smell like? Do you run some kind of Zyme product? Like HydroZyme or CannaZyme?

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I actually just flushed the system and replaced it with lower PPM solution. Upon inspecting the roots, most of them look pretty healthy. However, I found one or two plants with some small white spherical growths near the top of the roots. They look kinda like miniature white peas or something. I had some HydroZyme on hand so I added it today as a precaution.

The root system had a bit of a shock when the plants were about 1.5 weeks into vegging, as I had to separate some that had entangled. I had them originally in some smaller reservoirs, and I needed to transplant them, but waited a bit too long and the roots got tangled. I pulled them apart best I could, added some hydrogen peroxide as a precaution (2ml/gal), and bought the hydrozyme in case I saw any rot.

They look a bit burned to me...they dont need as much nutes as most 9 week plants...