Plant dieing in iws system

[Baron von greenback]

I have a plant in my iws system that started to dieing it looked like it hadnt been watered i tried topwatering pipes werent blocked roots looked good couldnt work it out so i decided to pull it so i started to rip the plants to bits to try and work out what went wrong then at the bottom of the main stalk were it meet the root cube there was a bit of mold inside the stalk was a bit of brown so it must of been stopping the plant take up water so if anyone else gets this have a look there guys

[trichomehi]

Not much detail to be fair, but i have had experience of stem rot due to growden cube being over saturated, mostly in plants couple of weeks in system, but never had one of those plants die on me, i usually just support the stem and remove pebbles away from cube until it drys, the saturated cubes in my case is from overflooding the buckets, which i do to make sure small root mass is getting plenty of solution, so i also stop doing this...