Is there a doctor in the house?

[daverabbit]

Hey what's up - this is my first real grow and I have some trouble I didn't expect. The plants were growing well, lots of fresh green growth and they responded well to some easy topping. But now 2 of the 3 plants have discolored upper fan leaves that have started to turn dry and curl up. I came too far to let them die so I did the only thing I could:

I went online to find people who know wtf they're doing.

Strain is White Widow, seeds from Crop King Seeds

Soil is Pro-Mix Potting Mix; to a noob, it seems to have most of what goes in to good soil. Lime, perlite, rock dust, worm casings, etc. I've grown one other plant before that was a frankenstein (not in a yield way,) using this soil and so far all seedlings have loved it.

Lights: CFL cause cheap and first grow. 8 26w 6500k bulbs. (HPS kit will be here tomorrow)

Nutes: none yet because I haven't gotten that far

Watered with distilled water. I don't trust the tap water here and I don't want the water to upset the Ph balance, or the soil somehow. Paranoid noob thinking. It's worked out great so far so I keep doing it.

Grow tent is a D60(?) 2x2x4 tent. Ventilation was pretty much static up until recently as this is in a basement and temps are fairly cool all year.

The temps in the tent fluctuate between 26C and 28C. There is a small fan blowing on the plants, enough to see the leaves moving on all 3.

This is almost the end of week 3 of veg

Thanks in advance for your help - I'm trying to do the best grow I can as a first time farmer.

 

[Dan Ultra]

IMO it looks like it might be getting a bit of pH lockout and having to pull nutrients from older fan leaves to continue growing. Have you ever pH'd your water? Even distilled water can have a huge pH range.

Not saying this is 100%, just what I am seeing. Do you have more pictures you could upload? How fast is it spreading?

 

[Dan Ultra]

 

[Major PITA]

Could it be heat stress/burn?
Did those leaves end up close to a light for a while?

 

[daverabbit]

Could it be heat stress/burn?
Did those leaves end up close to a light for a while?

CFL's are approx 4 inches from the plants, maybe a little more. Definitely not hot enough...

 

[daverabbit]

IMO it looks like it might be getting a bit of pH lockout and having to pull nutrients from older fan leaves to continue growing. Have you ever pH'd your water? Even distilled water can have a huge pH range.

Not saying this is 100%, just what I am seeing. Do you have more pictures you could upload? How fast is it spreading?

I have not Ph'd my water - do you have any suggestions for good products to use for adjusting it?

 

[Dan Ultra]

BlueLabs makes a decent pH pen, but if I remember correctly it's around $90. You can find cheap pH pens from fleabay of slamazon for about $20. They work ok, but need to be calibrated regularly

 

[daverabbit]

Just to add, I have not watered the plants since I moved them to the bigger pots about a week ago. There was a lot of condensation in the tent so the pots have held a lot of water. Would that contribute to Ph lock/nute lock? Currently letting them dry out with increased ventilation before I add anything

 

[daverabbit]

BlueLabs makes a decent pH pen, but if I remember correctly it's around $90. You can find cheap pH pens from fleabay of slamazon for about $20. They work ok, but need to be calibrated regularly

Cool...and just use Ph Up/Down to adjust the levels?

 

[Major PITA]

Unless your water really sux, that Promix should already be the correct PH and buffered with enough lime to keep it there.
I have one of the cheap yellow pen-style PH meters and it has worked great since I got it 2 years ago. I've calibrated it three times, but it has never drifted more than 0.1 PH.