Algae/fungal issue need pro advice please!

[Skunkbuster]

Hi guys, just asking for a distressed friend..
Plants have been ditched but just wanting to know what this shit is and how i can combat it? How do I flush this from the equipment? Is that what needs to happen? etc..
Grow details- happened twice so far .. all good up untill 12/12 switch, showed signs of clawing and generally unwell. Upon checking the roots this is what was found.. was advised that it maybe pithium.. used the stuff in the pic to condition the water.. prior to this crop all gear had been bleach cleaned.. the 1st of the 3 DWC crops was amazing.. the last 2 have resulted with this.. please help your guidance is much appreciated.

[Skunkbuster]

Was advised the pour and go was supposed to prevent this shit from happening but to no avail.. resevoir gets changed every 8 days, only feed 3/4 strength food, H20 temps are slightly above normal but not enough to cause this sort of out break.. thanks in advance guys

[Paracelsus]

DWC Likes a constant fixed cold temperature with little To No variation. 68° is optimal

[DW2]

Howdy Skunkbuster, What Paracelsus said. I try to keep my reservoir below 70° F. Also, I have a rule, If it can not be boiled or soaked in bleach, I throw it out. I use new air stones, water pump, and all lines for each new grow. I clean the reservoirs out with a 50/50 solution of vinegar and water first, soaking over night, to get rid of any mineral residue, then with soap and water. I finish with an over night soak with a 50/50 mixture of bleach and water. I use FloraShield (2 t0 3 ml/gal) during the grow to keep the unwanted microbes under control.
Good luck with Your grow.

[Paracelsus]

I fed my plants for the first time yesterday day 39 Veg
Nothing but water till now and I am going very light
Feed the soil