I believe i have stem rot, help and advice needed please.

[timmy77]

Over the last week i have noticed something on one of my plants near the base of the stem and it has gotten worse, to a point where it has affected the bottom branches and they have basically dropped off the plant, after a quick search of the forum i believe i have stem rot!

Im UK based and have been growing on & off the last 9 years with a "constant" grow the last 5 years, this is the 1st time i've had this problem is it savable? any help and advice would be greatly appreciated thanks, grow details below.

Soil or hydro or coco: Re-used Coco
Strain: Grapefruit(freebie seed from Attitude)
Photo or Auto: Photo
plant age: Planted @20th Dec, vegged until @20th Feb and started flowering @5th March
pot size: 15ltr air pots
has it been re-potted? and when?: Sometime in Jan from 1ltr normal pots to 15ltr air pots
Air temps (max min): @30-35 & 7-10 degrees Celsius
humidity: @50-60% via dehumidifier with auto on/off to keep it a constant %
lighting type and wattage (hps, led, cfl): 600w hps
Light schedule: 12/12 off during the night
Feed schedule and nutes (for hydro and coco): At the moment i water every 2 days with Canna Cannazyn 5ml, Growers Ark Coco bloom A&B 6ml per 2lt bottle and the plant is on 1.5x 2ltr bottles, next week il be adding small amounts of ATA PK 13-14 and Bcuzz coco bloom stimulator to the mix.











*Edit sorry for pics not being the right way :/