Quote Originally Posted by kallidah
I am using premeasured Micro and grow nutrients that came with my system from manufacture.
Thanks for any help!
Are you using them at the same time? Knowing the brand name, dilution rates and N-P-K values might help.

I'm a soil guy, but brown spots can be from root rot, calcium defeciency, ph swings, heat and sometimes bugs.

Just brown spots...no yellowing?
What do your roots look like? (stringy and white, or brown and slimy?)
What is your bubbler schedule?
Have you ever added H2O2 (hydrogen peroxide) or any other additives to your reservoir?
What does the new growth look like? Old leaves are old news, and old necrosis (brown spots) will never 'heal'.
Is the problem spreading upwards?

If using sample packs of off-brand nutrients, I'd start looking for a replacement regimin asap, and post a couple of pictures of your ladies if possible.