Okay, need some advice. I’ve got a very early sign of some sort of deficiency, I think. But it’s so early that it’s hard to tell, so I wanna know what you guys think.
DWC, not recirculating
Tent temp: 78
RH: 62-65
VPD: 1.1
Res temp: 68
PPM (500 scale): 600, up from 460 earlier today
Water: R/O
Nutrients: GH - on week 3 recipe on feed chart posted below
Light ePar: 475, down from 525 from earlier today
Just noticed a few blemishes on my leaves today. Burnt leave serations and few rusty/purplish spots on leaves on the same cola, although very small and barely noticeable. But I’ve run into this issue before when I was running tap water, and it cured the problem when I switched to R/O so in case it’s the same issue, I’m not sure what the cure would be this time. Also have some purple-ish stems, but I’m growing GDP so I’m not sure how to interpret that since it could be genetics.
I figured my PPM was a little low at 460 for the size of these plants, so I upped to 600 and lowered the light just a little in case it’s light stress (highly doubt, but just to be safe).
Thoughts? What do you think the issue is? And do you think I did the right thing to fix? Suggestions please! I need to fix this early.
Is it 5.8 all the time or do you let it fluctuate up and down?
When I do hydro, the nutrients I use always go down , so I start them off at 6.3 and let them go down to 5.6 then adjust them back up so all nutrients are available.
I usually ph to 5.7 and let it get to 6.0. The longer I go between res changes (1-2 weeks) the longer it takes to drift, so I don’t go below 5.7 because after a few days to a week it’ll take too long to drift back up to 6.0
You start at 6.3 and it goes down?? I’ve never heard of ph drifting down in hydro, that’s a first. Most hydro guys I know always say it’s supposed to slowly drift up naturally
I would be making sure my root health is still good. Im not a hydro guy but have read a ton about it. Purple near buds and rusty spots on upper leaves concern me.
morning @gummytape I am also a DWC non circulating grower…I use the same nutrient line as you but not at the strength suggested by GH…this is my current feeding schedule
I think what you are seeing might be due to overfeeding,…all your info looks to be ok to me except ppm is high from my experience so maybe just watch and see if more appears…and in hydro during veg the plant will want more Nitrogen and when it takes in nitrogen it will push the ph towards 7 and then during flower she will take in more of the Phosphate & K (potash) which will drive the PH towards 4…I don’t adjust PH in between change outs…
Is it possible I have a calcium deficiency? I’ve read that the ideal PH for calcium is around 6.2, and the symptoms match a lot of what I’ve seen. Spots on middle and new growth, purple stems, and the leaves most affected are most exposed to the light. I guess another symptom is an increased intolerance to heat and light?
I’m gonna run my ph at 6.0-6.2 for a couple of days and keep y’all posted, because if it truly is calcium then raising my ph will stop the spots from forming.
If your ph stays upper 6 and at 7, then maybe that’s why you don’t get what I’m having. Your ph is ideal for calmag uptake according to what I’ve been reading up on. Dark leaves are a symptom of overfeeding but so is Ca def
Yeah same. Roots look fine to me, not slimy or smelly. Root rot tends to affect the whole plant at the same time doesn’t it? Never had it so I can’t say from experience. But I run peroxide and my res is 67, plenty of oxygen. I doubt it’s root rot
best advice don’t react too quickly…stay the course as sometimes they just show bad signs that are not what the whole plant is experiencing…oh and lets eat something
Definitely a calmag issue, it progressed a bit but it only affected a few leaves before the burning stopped! You can see a bit here. All seems good now, seeing some healthy growth
Good eye for early signs of deficiency!
This is most likely a Ca Mg issue.
It is commonly overlooked and it is one of the most common deficiencies, as cannabis is a Ca hungry plant.
Most base nutrients don’t include enough Ca or Mg, thus the use of a supplement such as Procal, Cal-Mag, or Calimagic is suggested with any base.
If you are using a Ca Mg supplement and seeing this, keep an eye on pH/PPM and keep a 30-40x magnifying lens available to check for pests. Thrips can cause this sort of leaf damage.
Examples of both Thrip damage and Mg deficiency:
