recently i had my plants start to die on me iin the last week of flower. It happened to three out of the four even with the one surviving one sharing an nft with a dead one.

I told my friend about this and he told me to look out for a brown ring inside the stem which it did have.

Im just wondering what it is and is it anything to worry bout in future crops?

Sounds like root rot - what were the roots like?

Are they in rockwool? if yes then you may have had the water flow to high keeping the rockwool to wet.

Yes there in rockwool.the flow is on the lowest setting... would i be better sticking the pumps on a timer say 30mins on 30mins off.

THe roots didnt look too bad in my opinion. Slightly off white but nothing major... How would I prevent root rot in the future.

Cheers for the replies guys.

Most likely Phytophthora, verticillium or fusarium, once inside the plant there is no cure known. Some pretreatments may help stop infection for fusarium, but not the other two.

All are highly infectious, any equipment that water via root/plant contact will reinfect. Thats pipes pumps reservoir ph and ec test equipment, jugs etc will reinfect unless sterilised.

Do not let the rockwool get saturated.

I use Cannazym it breaks down old dead root matter keeping good roots healthy.

Hello acienicho . . . If as suggested by OT1, it is one of these ailments, you are in serious shit ! I don't have the energy to write it all out again. If you want to know anything please dont hasitate to pm/message me . . good luck mate

Hello acienicho . . . First, if this was my crop, I would chop the remaining plant immeadiatly ( she is already infected ), then blitz EVERYTHING, by "blitz" I mean steralize and not some half-arsed attempt . . . I cannot emphasise enough, how potentially serious this is. It is one nasty f**ka, that can decimate your crops for years to come, no exageration ! Next, you have to tackle your enviroment, I am praying that you grow in a tent ( as this bis pretty striaght forward to clean ), if you do not then you have one ball-ache on your hands ! Everything must be cleaned with a similar made-up solution, walls, carpet, ceilings, vents etc. Pathogens can lie dorment, for one, in dead roots, hence the minutest, microscopic piece of dead material left behind is enough to infect and kill your next crop its one contagious nasty bastard. As for future crops, there are to ways to approach it . . . one is to add beneficial microbes both to your rooting medium and nutrient solution, these will colonise around the roots and form an active defence. The other is to " cleanse" the water, reverse osmosis, UV steralizer or add products like liquid oxygen ( hydrogen peroxide ) or Pyth-off, these will kill all the nasties in the water. Obviously, you cant apply both methods at the same time as these latter products will also kill all the good bacteria/microbes in the water. Has my understanding goes . . . pathogens, like pythium are all around us, in our day to day lives, yes there in all your growrooms already !However, they only attack plants already stressed, ill or damaged in some way. If this is correct, then one of the best forms of defence is to start with healthy plants and maintain them. Unfortunatly, once these spores multiply and get a stranglehold ,they can even bring healthy plants down - which is where I am. I,m also starting a new thread soon regarding ozone which maybe useful. . . BUT ACT NOW !