They are really far gone, but my advice...
Pull them out, hang them over the sink and spray them directly with a 3% h202 solution. Give the roots a slight tug and remove what you can. Spray them off really well with water, and snip any really bad ones that remain.
Prepare a fresh res and...
No worries. The important thing is that the slime is purged from as many dwc grows as possible. Feel free to ask whatever you like. I have a years experience fighting the slime, and now a years experience growing with it successfully gone. The slime is the only thing which I hold a grudge...
Brown slime algae is easy to address and cure in a DWC with a microbe tea. I would post my recipe but Farmer Jon has already posted it word for word a few pages back. You can refer to his post for my instructions.
Forget constant sterilization. Breed active bennies for 2 days, sterilize...