Root issues

[Sweetpea.kern]

I have two mother plants that are 6 weeks into flower and i'm starting to see some brown roots with black spots on the secondaries ? No slime. They are in RDWC, water temp is 70 degrees, ph is a little higher then i normally keep it, sitting at 6.7, ppm is 450 ( i did a phed flush 4 days ago and gave nutrients at half strength.) using current culture nutrients.Air in all the buckets. Any suggestions ? They are super unhappy ;o(

 

[Phases]

I just went to the hydro shop and asked them what they thought I could do to fight some mild root rot in my flood and drain tables and I was told that SM-90 would help along with Subculture M by GH -
As I have read about some tea mixes that have a lot of beneficial bacteria and stuff to combat root rot.
So I went for the subculture and SM-90 combo.
I used to do the old h2o2 treatment but the brown roots kept coming back. So maybe using h2o2 to kill off all the old dead stuff and then introduce some subculture or bennies ? Just a thought I by no means have a ton of experience with root rot- the last time I did dwc I got a bad case of it and just used the h2o2 method and just made sure to keep adding it to the Rezz.

Anyways hopefully someone else has a better idea on this. But that's my 2c

Good luck and good vibes...