Fusarium!!! Experience needed...

Ok i know pics are useful but did not take any before i chopped the plant. On my last 2 grows, plants were infected abut 1 inch above the main stem. One of the plants recovered on its own stem thckened nicely where it was dampening off. but it was a male.(when it rains it pours) Is there something i did wrong or is there some spores still lingering in the closet.
Grow setup includes
cfl 4 seedlings (24hr)
400w HID (veg)(18/6)
400x HPs (flower)(12/12)
Fox farms - Grow big,Tiger bloom,big bloom
Tecnnafloras - Sugar Daddy
Rockwool growing medium, aquarium gravel on top of rocwool
Ph is around 5.9 - 6.2
No ppm meter ( i know!!! money shortage right now please forgive me)
using nutes at 1/4 strength
Air stone in res
Temp - 75 day 68 night relative humidity between 33% - 40%
Bag seed from some choice Kind

Please if there is anybody out there with some knowledge about fusarium or how to treat it please post. All information would be greatly appreciated.

I would say that you didn't clean your closet prett good at all beacuse I had the same problem, but not with MJ. I had some flowers growing in my room and they had the same problem because i didn't clean my window.( I had them next to the window!)

so how would i go about getting rid of it in the room. And is there anyway to treat an infected plant? thanx again kaos

i would suggest cleaning your room really well. And i would suggest your ph being at 6.5.
try that and see what happens. what does the infection look like? can you describe it more?

well early on the stem just looks a little scraped or damaged in just 1 spot. On all the plants in both grows, it gets about a half inch total in height going up the stem then it starts drying out the stem that is brown, the stem above the brown is perfect and much thicker. the last plant i chopped the stem was so dry and brittle in that spot that it was cracking and you could see through it in spots. thanks again i need to make sure this doesnt happen anymore

6.5 ph is high for hydro i use around 5.8 - 6.2 is there another reason you suggest this? some nutrient that takes in better at 6.5 that could help maybe

thats too high of a pH for hydro. they recommend in the 5s no higher. ya gotta clean the closet good cuz the pollen is microscopic and the fans blow it around everywhere. those pph meters are EXTREMELY important in hydro setups. ya need one of those stat.

yeah i keep my ph in the high 5's low 6. I am working on the ppm meter but money is really tight after christmas but is on the top of my list