Pic - What is this discoloration?

[lazyfish]

Hello and Happy New Year!

I was hoping somebody might be able to have a look at this here leaf.

It is sort of darker and shiny green/blue looking between the veins. The smaller leaves at the top of the photo are sort of deformed at the tips.

Here is a (more) healthy leaf:

I have been keeping track of the nutrient intake and pH. Flowering nutrients are .10 .85 .55 (NPK). I just upgraded to a 600 watt HPS, could it be a light burn? The light is maybe a foot away from the plant. Temps are 60-80 degrees F day/night.

White Widow week 5.

Thanks y'all!

 

[Weaselcracker]

I'm not sure about the discoloring, but it could be overheating, based on the fact that the leaves are curled up like that at the edges. Your temps may be 80 in the room, and 12" away should be a safe distance, but it's easy to get a hotspot under the bulb. The solution for this is to have the oscillating fans blowing directly above the canopy to even out the temps, or raise the lights a bit.

 

[lazyfish]

Hmmmm. I have an oscilating fan going...

Thanks for the quick reply, Weaselcracker. You got member of the month??? Wow! I am not surprised, though, you have always done me good. Congratulations.

The buds on this plant are doing fine otherwise the minor discoloration. Right after the light went out, I had a look with a flashlight and the discoloration might be purple... or brown? I might be a little colorblind.

 

[Weaselcracker]

Thanks Lazyfish. . I've had that sort of discoloring before and in my case it was from persistent overwatering, and possibly cold night time temps. In that case it got quite bad- and another symptom of the deficiencies caused by overwatering was that the leaves and stems got very brittle so it was easy to snap leaves off. Also some plants will naturally have a bit of purple coloration, which also is enhanced by low night time temps.
I suspect none of this applies to you though.

 

[lazyfish]

I have actually been trying to lower the temperature in the room, but with the new 600 watt HPS, I can't get below 60 degrees F at night.

The stems are pretty sturdy as far as I can tell.

As far as over watering goes... I flushed it about 5 days ago and have not watered since. I noticed the smaller deformed leafs right before I flushed.

I flushed as a formality; it is something that I have done in the past and it seems to have helped before.

 

[SevasTra]

could be an excess of phosphorus, or could be low night temps. those are my two pennies!

 

[ConstantGreen]

I also think it could be cold night temps. If your grow is in the 80's with the lights on and dropping to 60 when off that's enough of a difference to affect the chlorophyll pigmentation I think.

 

[DeanB]

I have the same looking leaf and my temps are 80 in the day and drop to 60 at night. My grow area has one wall that is concrete and an outside wall. I should insulate it, lol. I'm pretty sure that's what it is, the low temp. Mine are still in veg.

Edit: the only nutrients they have had is 7-7-7 npk

 

[Papageno]

There is for sure minor over heating but nothing too drastic. But the nutes are too high. There is a large range for nutes. You can run them half what you are doing and still get great results. The current level is showing multiple signs of over doing it. Soon there will be some good nute burn. In 3 weeks or less depending on how good you do (doing great means sooner) you MUST cut then in half.

I will paste a chart below showing many factors throughout the grow. It is a very standard 3 month hydro grow. You may be longer than 3 months but the trend holds true. If any of that does not seem obvious then ask and we will explain. It is hard to tell without full plant pics but I am guessing you are on the downward slope of the EC curve. I bet stacking has formed and you are looking at resin top off stage and need to be cutting it down dramatically.

Flush the res and drop the EC to half where it is.

High nutes don't make better weed.