if you got sludge in your chiller,and kill it with h202 or bleach,it dies.trouble is,its organic,so dead,eventually it will rot,inviting back more trouble..i suggest sterelizing it,blowing it out with a high pressure water hose to rinse residue out,then spitshine the system,buckets and all..when you refill,use some stress-zyme to eat the little bits of yuck you wernt able to get..it wont hurt your plants,and will keep your res clear with proper use..plus,its cheap and found everywhere,like wslmart,target,ect..i used old cones with bad rootd,a whole root mass died,theplant regenerated roots and lived,but a whole double handfull of roots were in the basket..i had no problems,the enzymes ate all if the old shit without any slime,ph flux,ect..
hope this helps.good luck!