Having trouble with a diagnosis, ideas?

DarknessFYC

Active Member
Rdwc
RO water
GH 3part+calmag, total ppm 1200
50 days old, still in Veg
79f lights on, 63f off. 35-50%RH
PH checked daily, has not been over 6.2 or under 5.6.
2 1k MH lights 22" above canopys

I have 8 plants in the system. 3 other plants show the same issue but very light, only on 1 or 2 leaves. I noticed it starting about 5 days ago on this plant but didn't think it was a big deal, now that it is starting to show on a couple other plants I am getting concerned. It does not show on the newest growth and seems to be effecting only fan leaves. Plants have been in rdwc for 3 weeks. The only thing I know that I am doing "wrong" is that I forgot to pre-wash a portion of the Hydroton which seems to has stained the water and the roots but I can't imagine that is causing any problems. Haven't done a res change yet but will do tonight.
Any ideas? Thanks!
 

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DarknessFYC

Active Member
Yeah, water has been piss yellow from the beginning. And I have hydroton "dust" circulating. Most of it has settled to the bottom of the sites and res but it definitely contributed to the color of the water
 

farmerfischer

Well-Known Member
The leaves look almost like a mag issue but you state your using cal-mag already which is good when using ro water. The res should be cleaned and replenished every two weeks and if the res temp is to warm u can cool it with frozen bottles of water
 

DarknessFYC

Active Member
The leaves look almost like a mag issue but you state your using cal-mag already which is good when using ro water. The res should be cleaned and replenished every two weeks and if the res temp is to warm u can cool it with frozen bottles of water
Yeah, I started this res with the calmagic recommended dose of 5mil/gal which gave me way too much @ 500ppms. I removed 30% of the water and refilled with PH water and I have not replenished any calmag since but I would imagine there should be more than enough left. Your right, a res change is probably the best way to eliminate any variables and zero in on the problem.
I have been tossing 2 frozen 2 liters in twice a day but with 35gal in the system it doesn't do much. They melt within an 45min. I have been contemplating a chiller, might have pull the trigger on that.
 

DarknessFYC

Active Member
6 weeks later i am still fighting this. It has been hanging around throughout the grow sometimes 20% of the fans other times 5%. The only thing that tends to help is res changes but I do not have enough data to say that for sure. I am running a chiller and hydrogaurd and every res change has been cleaner than the previous as I have been learning how to maintain it. Roots are great other than some nute stain. All my parameters are within acceptable ranges except I have had some light burn/heat incidents in the last few weeks. I think the biggest tell is the purple stems. On the fans that are affected, or soon to be affected, stems turn purple and soft. Even the stalks will get purple stripes. From everything I can tell there are only 2 deficiencies that cause this, Mag or more likely Phosphate. The leaves get dark green, thicken and get brittle and then discolor and die. It shows up on all levels of the plant but mainly on leaves directly exposed to light.
I am 3.5 weeks into flower and 7 days from the last res change and the issue is more prevelent that it ever with 25% of medium to big fan leaves showing spotting and 60% of all stems turning purple. My RO water mixed with a little tap water left in after flush is about 50ppm. I add calmag first up to 250ppm and then the rest from there. I am using a custom generated feed chart from GH website, dosing is way more proper with that than their genaric chart. During top offs I have been adjusting calmag, bloom and bloom bosster up by 30% and minimizing the "grow" nutes hoping to provide more phosphate but it hasnt seemed to improve the sitch. One of the pics shows a fan that is normal next to two that are starting to turn. One shows some "shredding" that has been hanging around too.
Ideas?
 

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farmerfischer

Well-Known Member
Wow!.. try using just the flora bloom and micro.. gh tends to be a bit to high on nitrogen for cannabis.. brittle thick leaves are usually a sign of toxicity.. the rust spots are really bad.. not sure what's going on if you're using cal/mag .. phosphate deficiency in my experience usually manifests as nitrogen deficiency (looking yellowish at first)
 

trippingballs

Active Member
6 weeks later i am still fighting this. It has been hanging around throughout the grow sometimes 20% of the fans other times 5%. The only thing that tends to help is res changes but I do not have enough data to say that for sure. I am running a chiller and hydrogaurd and every res change has been cleaner than the previous as I have been learning how to maintain it. Roots are great other than some nute stain. All my parameters are within acceptable ranges except I have had some light burn/heat incidents in the last few weeks. I think the biggest tell is the purple stems. On the fans that are affected, or soon to be affected, stems turn purple and soft. Even the stalks will get purple stripes. From everything I can tell there are only 2 deficiencies that cause this, Mag or more likely Phosphate. The leaves get dark green, thicken and get brittle and then discolor and die. It shows up on all levels of the plant but mainly on leaves directly exposed to light.
I am 3.5 weeks into flower and 7 days from the last res change and the issue is more prevelent that it ever with 25% of medium to big fan leaves showing spotting and 60% of all stems turning purple. My RO water mixed with a little tap water left in after flush is about 50ppm. I add calmag first up to 250ppm and then the rest from there. I am using a custom generated feed chart from GH website, dosing is way more proper with that than their genaric chart. During top offs I have been adjusting calmag, bloom and bloom bosster up by 30% and minimizing the "grow" nutes hoping to provide more phosphate but it hasnt seemed to improve the sitch. One of the pics shows a fan that is normal next to two that are starting to turn. One shows some "shredding" that has been hanging around too.
Ideas?
I used to run DWRC with GH but now I run ebb and flow and don't have these horrible problems.

I think your calmag levels are ok. This is what I would do you can take my advice or leave it.

-It's too bad you are so long into bud, I would have advised a foliar feed twice a day up to week 2 of bud.

- first run just low EC water 0.4EC in the system for a day or two, then do a res change.
-add calmag at your levels of 0.4 EC and then use equal parts of the 3 part to get your EC back at 1.7 or 1200ppm like you had it at.
-Continue using this formula until you flush
-Do a res change every week!!!!!!!

If you do this you might get some decent bud out of this run because you have salt lockout.

IMO your problems could be from not doing an initial res change often enough, which causes nute lockout as the nute profile changes depending on what the plants take up. Foliar feeding can help restore balance in this situation, but you are a bit far along to spray.
 

DarknessFYC

Active Member
That looks like phosphate issue. Any chance the problem plants arent getting enough o2 in the water. That can trigger p lockout.
I am running what basically is a WaterFarm setup from GH but with upgraded circulation. I have the drippers running water through the hydroton plus air stones in every site including the control and res. Chiller running at 68ish degrees. I can't imagine it's an o2 problem. Thanks tho
 

DarknessFYC

Active Member
I used to run DWRC with GH but now I run ebb and flow and don't have these horrible problems.

I think your calmag levels are ok. This is what I would do you can take my advice or leave it.

-It's too bad you are so long into bud, I would have advised a foliar feed twice a day up to week 2 of bud.

- first run just low EC water 0.4EC in the system for a day or two, then do a res change.
-add calmag at your levels of 0.4 EC and then use equal parts of the 3 part to get your EC back at 1.7 or 1200ppm like you had it at.
-Continue using this formula until you flush
-Do a res change every week!!!!!!!

If you do this you might get some decent bud out of this run because you have salt lockout.

IMO your problems could be from not doing an initial res change often enough, which causes nute lockout as the nute profile changes depending on what the plants take up. Foliar feeding can help restore balance in this situation, but you are a bit far along to spray.
I think your def right about the res changes, I had been going 12-21 days between. I had been feeling confident because the water had been looking good and I wasn't getting any slime on anything like I was the first couple changes so I felt I could run longer without it as long as I topped off with 1/4 strength nute water. After your suggestion and a conversation with a very experienced grower, I realize the lack of changes is the root cause. I will definitely get changed out Sunday.
I haven't really took the time to understand/learn how to/when to foliar feed but it seems like an effective way to mitigate problems by bypassing the roots. I need to read up on it.
Thanks for the input
 

trippingballs

Active Member
I think your def right about the res changes, I had been going 12-21 days between. I had been feeling confident because the water had been looking good and I wasn't getting any slime on anything like I was the first couple changes so I felt I could run longer without it as long as I topped off with 1/4 strength nute water. After your suggestion and a conversation with a very experienced grower, I realize the lack of changes is the root cause. I will definitely get changed out Sunday.
I haven't really took the time to understand/learn how to/when to foliar feed but it seems like an effective way to mitigate problems by bypassing the roots. I need to read up on it.
Thanks for the input
To foliar feed -

take some water out of your res since it is already ph'd and ec'd and put it in a spray mister and mist the leaves 15 minutes before lights on. I only do this until 14 days into 12/12 to avoid depositing minerals on buds. You might want to dilute it with some PH neutral RO water to get it down to like 1.0-1.2EC so as not to burn the leaves.
 
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