You need drainage in your soil. perlite, vermiculite, small 'aquarium' stones, or sand will all work. perlite is my favorite. The lack of these is probably causing your plants to show signs of over watering.

What has a Ph of 5.9? The Ph of your soil should be about 6.5, and the ph of your water around 7... sometimes using cheap generic plant food (anything not designed specifically for weed) can drop the ph of your source water so be sure to test your nute solution and keep it in the 6.3-7.0 range.

hope this helps you out :thumbsup: