Yellowing and dying. Help please ASAP

Sorry I do not have any pics but I will break it down to you as clear as possible. I think the prob may be my methods but here goes. I was vegging in the aerogarden, grew six plants well past six nodes, healthy, lush, and low and bushy. When the time came I cloned and transplanted the six into an 18 gallon DWC using 12 gallons, cal-mag additive, h202, superthrive, and Fish Emulsion.
This is where the problems started. I let my res temp get to high (fixed) and experiance root rot. the fish emulsion became a fish sludge. goo all over my roots. older fan leaves became very yellow and many began to die. so I rinsed the roots and flushed the system with a light solution of cal-mag, ST, and h202. Same problem. Now in only one week growth has been extremely stunted, prolific yellowing, and brown spots starting at the tips of the fan leaves and moving towards my stems. New growth is also narrow looking and pale. . Lighting is about 12000 lumens for veg and adequate ventilation. No pest either obviously a defenciency or disease. Help Help please! Plants are 5 1/2 weeks from seed.

GROWFAQ with out pix all i can recommend is these plant problems

Thanks THC I have that page and oddly enough my plants look nothing like any of those pictured. I would have to say possibly Nitrogen deficiency but it looks like it may be a potassium def, yellowing then browning from the tips then dead spots on the leaves, I will just flush and in one week when my fox farms nutes arrive starte a new feed schedule.Hopefully they will survive until then. Its funny how one week ago these plants were thriving and then now they are going to shit so fast in only one week.

when root rot has progressed to the extent that you describe, it is, unfortunately, unlikely that you will save the plant. I do not say this lightly, as usually I would say never give up on a plant - but this is probably the worst scenario.

Have I cheered you up yet? Well, all is not lost mate.

The first thing you should do is take a clone or two from each plant incase you lose them. As you know they will carry the age of the mother plant so will only need a short while in veg to grow roots.

Bear in mind that at this stage of decay the plant can only grow new roots - and not regenerate old ones, so it willl need as much help as possible.

there are root shield products you can buy to help your plants - put in nutrient solution.

also increase oxugen supply to nutrient solution as much as poss and aim for a ph of about 6 fo next week or so.

you did well with the hydrogen peroxide, B1 (thiamine) also helps root development.

change nute solution regularly ( every 4-5 days ) over next 2 weeks - good luck.

Dave you are frightlingly correct. I checked yesterday and did another water change. The goop cleared up on the roots, but about 85% of the root mass on the two worse plants was brown and soggy, but, there was no foul smell, they actually smelled like fresh roots. I trimmed offthe worse of the roots and yes the plants were cloned. The clones are doing great its been 1 week now for them. Could the fact that I cloned and transplanted the plants at the same time play a role in my problems or could it have been the emulsion? Has anyone else used Fish Emulsion for a DWC Grow? I used 4 teaspoons to 12 gallons

certainly not the cloning or transplanting that caused you any problems - methinkd something fishy might be to blame as you rightly suspect!lol.

glad you got sorted mate, good luck.

Cannibus is an amazing plant! Hydroponics is the shit! As fast as those plants went from good to very bad, they are recovering!!! 2 days of flush, and a some root trimming and all plants are recovering wonderfully! The worse one is the one which had the most root trimming, which is expected. I basically trimmed it almost down to a newly rooting clones stage. The rot was that bad on this one. This plant was right on the hot spot in my res, and was sadly my nicest. It was FIMd very early , which resulted in a very bushy plant with six main bud sites. Hopefully I can still save it. I think I am going to try and leave this solution in for two weeks or more, just topping it off with ph'd water