I have them doubled because the first cups have drain holes poked into them - the bottom has a spacer to allow water to drain so its not sitting in the top cup. But if you say they need oxygen and that the double cup is stopping it ill change it.

What do you suggest i do about too much nitrogen?

And about the piss, deer park water. no piss. lol.

Ill start using tap water. Why not use distilled water? and how will I be able to know when the plants are hungry? (for fertilizer I assume)

Thanks for the help guys