Early problem, yellow patches

[Haunts]

I have 2 heavy weights at about 3 weeks old but one of my girls has developed an early problem, with the cold weather setting in i wasn't sure if the temps could cause this, ive noticed my hygro says a minimum of 16C at lights off but it is only happening on one of them.

Your Equipment:
.1) Type and wattage of lights. 150w HPS
.2) Distance from tops? 8 - 10 inch
.3) Reflector type? Bat Wing
.4) Is there a consistent fresh air supply? Yes
.5) Do you have an exhaust fan and a circulation fan? Yes
.6) What schedule? 18/6

Your medium:
.7) Specific brand and type of soil, Plant Magic Soil Supreme
.8) Size of container. 4-5L

Your growroom:
18) Indoors
19) What size of closet, room or hut? 45cm(18in)x45cm(18in)x80cm(31in)
20) What are the temps and humidity levels while lights are on? 25C, 30-40 RH With lights off? As low as 16C 40-50RH
21) Have you seen signs of insects in the growroom? No

Your strain:
22) What strain are you growing? Heavy Weight
23) Is this an photoperiod strain? No
24) How old is the plant? 3 weeks
25) In what life-cycle is it? Vegetative
26) From seeds or clones? Seeds

 

[Fantasy Island]

Looks like you splashed nutes on her. The one touching the soil loooks like its getting burned from touch the soil

 

[Haunts]

I hadn't given any nutes when this started, could it be from just the nutes within the soil or perhaps plain water splashed and then the intensity of the light?

 

[Hal 8999]

Even plain water under bright light can burn. Just keep the leaves dry.

 

[Haunts]

Ok thanks for the help

 

[Waira]

Haunts-- both pH and certain nutrient transportations are temp sensitive,.. res' did get too cool I believe,... pattern of damage doesn't look like lensing burn to me, more likely it was a temporary rapid pH shift from the temp drop-- have a look--> rapid pH flux-- https://www.autoflower.org/threads/quick-and-dirty-deficiency-picture-depot-expanded.43164/page-2
... maybe get a small aquarium heater in there,...

 

[Haunts]

Cheers Waira, i've gotta small tubular heater in my cab but the cab is in the garage where its a bit chilly. I might have to switch my light schedule to 22/2 or something.

 

[Nabzter]

I have seen this on heavy weight fast and vast and only ever on that strain. I found it was a fungal infection due to lack of air circulation.