2nd plant ever

It's easy enough to get oxygen into the roots and also to combat potential fungus in the soil.... add some H2O2 to your water! You can't really overdose on H2O2 and it will not affect either your ppm or your pH so try about 1/4 cup of it to a gallon and thoroughly soak your pot. Then the hard part ... you've got to wait until it's bone dry before giving it anything more. Keep lifting the pot when you think she might need something - if you feel any weight to it at all, do not water/feed.... Weed must have a wet/dry cycle to properly grow and overwatering, rather than being "a lot of water" is in reality the state of being constantly wet... which will lead to root rot, fungus, droopy leaves and a very sick plant. Most gardeners will kill a plant by overwatering than underwatering... So make this a habit of yours - always lift the pot before you give it water/feed... make SURE it's very dry... it will be better for the plant if it goes one day too long between waterings than one day too soon. Good luck....

Major potassium deficiency.

I am SOLIDLY with Organoman here...