Splotchy lime green coloration on new growth, spreading to bigger leaves

ancap

ancap

Active Member
Hello all,

I am growing hydro out of my BCNL Producer. My feminized northern lights plants are 18 days old from seed. The ph has remained stable (between 5.6 - 6.2), the ppm of the nutes has not changed, and the temperature is in a healthy range. However, I've noticed the development of a lime green splotchy discoloration on the new growth and top leaves. Is this something to be concerned with? It is effecting about 6/8 plants so far.







This is also a little concerning. This brown spot has been spreading on these leaves. These particular leaves are getting a heavy amount of wind action from the fan right next to it. Any connection? What could this be?

 
talon90

talon90

Active Member
thats burn marks like a magnifyng glass off that foil you have below it get rid of that foil man asap and the lime green is normal for new growth as you are using a dark time at the moment weather it be 18/6,20/4,12/12 its just from the dark period fresh growth dont stress on that and if your using nuts lay off just incase thats lack of mag , use epsom salt just to make sure it wont hurt it
 
ancap

ancap

Active Member
Thanks for the reply. The tin foil hasnt been hurting any of the other plants at all. I've been told by others who grow out of my same system that the moist rockwool will sometimes develop an algae if left exposed to the light. Thoughts on that? Good thought though, I'll take the tin off of that one and see if the spots grow.

My ppm is around 580 right now, though 170 of that is my hard water. The nute ppm is around 410. Using two 400 watt mh lights. Light cycle is 20/4 right now.
 
talon90

talon90

Active Member
well on the algea thing i have never heard much on that so i couldnt give a reply on that as if i knew cause then i would be a lyer lol......
 
ancap

ancap

Active Member
Dude, I am so pissed off right now... at no one in particular. I woke up to find this problem on my plants spreading. I did research last night, and I know this isn't nutrient burn. If anything, my nute levels are on the low side. My ph was reading 6.0. I've been trying to keep it lower, but my tank naturally raises ph throughout the night. I knew this was a nute deficiency, but couldn't figure out why.

Then it occured to me that I should check the accuracy of my ph pen and calibrate. Now, don't get the wrong idea... I've been recalibrating about once every 5 days to be sure (and storing the pen properly, keeping the censor in a ph solution). When I put the pen into the ph 7 solution, it read 7.6. This means my actual range has been more like 6.5 to 6.8 and sometimes higher until I could adjust. I attempted to lower the calibration with the screw, but the device refuses to lower below 7.6. It will raise, but not lower. I figured my best option was to raise to 8.0, retest, and add 1.0 to my reading until I can get a new fucking pen.
 
kno

kno

Active Member
ancap said:
Dude, I am so pissed off right now... at no one in particular. I woke up to find this problem on my plants spreading. I did research last night, and I know this isn't nutrient burn. If anything, my nute levels are on the low side. My ph was reading 6.0. I've been trying to keep it lower, but my tank naturally raises ph throughout the night. I knew this was a nute deficiency, but couldn't figure out why.

Then it occured to me that I should check the accuracy of my ph pen and calibrate. Now, don't get the wrong idea... I've been recalibrating about once every 5 days to be sure (and storing the pen properly, keeping the censor in a ph solution). When I put the pen into the ph 7 solution, it read 7.6. This means my actual range has been more like 6.5 to 6.8 and sometimes higher until I could adjust. I attempted to lower the calibration with the screw, but the device refuses to lower below 7.6. It will raise, but not lower. I figured my best option was to raise to 8.0, retest, and add 1.0 to my reading until I can get a new fucking pen.
Click to expand...
The pH scale is logarithmic and as a result, each whole pH value below 7 is ten times more acidic than the next higher value. For example, pH 4 is ten times more acidic than pH 5 and 100 times (10 times 10) more acidic than pH 6. The same holds true for pH values above 7, each of which is ten times more alkaline (another way to say basic) than the next lower whole value. For example, pH 10 is ten times more alkaline than pH 9 and 100 times (10 times 10) more alkaline than pH 8.

TLDR: you need to calibrate not add 1pH to an off meter, good luck!
 
ancap

ancap

Active Member
Wow, didn't know that, thanks.

I had a pretty lengthy discussion with my BCNL rep about this after he looked at pictures. He thinks at this age, it is most likely from A) bugs or B) more likely too much nutes causing a lockout. He doesn't think a ph that is off by 0.5 would cause this kind of problem. Given that these aged plants could easily grow without any nutes at all, it it most likely not a nutrient deficiency (He was not saying I shouldn't use nutes, but just making the point that young plants can survive without).

I am readjusting the reservoir and bringing the nute levels down, and also spraying for bugs just in case.
 
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