From what I understand, continuous aeration will cause the iorn to 'fall-out' and settle on the bottom of the resevoir. (it oxidizes)

There should be no reason to aerate the water for extended periods. Just a few minutes is fine.

Leaf issue sounds like possible overfertilizing. Plus, during the winter soil holds the moisture longer.

How big are the pots, what soil, what k.....

Ya know...it would really help if you filled-out the troubleshooting form as best you can. Playing twenty questions or guessing, isn't a good way to troubleshoot problems. At least not from this end, lol.
Rusty Trichome Reviewed by Rusty Trichome on . Airstones and defeciencies Hi all! Okay so here is a problem I have been experiencing for some time now. I use a 45 gallon trash can with a hose and watering wand to do my watering. I fill it with H2O after each watering, and bubble it with the airstone until the next watering(every other day). I have noticed at the end of my cycle, around the 7-9 week mark, that i get a pretty significant leaf curl around the edges. I will post a pic later when lights are on, but it is on the outside edges not the tips. It is like Rating: 5